- Drug Science
Tolerance to LSD – How the Brain Bolts the Doors of Perception
Is microdosing LSD safe, and does it really have its alleged benefits? Answering this question requires understanding tolerance to LSD.
Not what you are looking for?,
Join us for a day on the integration of research across disciplines and practice, and explore with us innovative tools to solve some of the complex problems of today.
The event is all-free and will take place via Zoom. Invitation links will be sent via mail to all registered guests (RSVP below).
Research Fellow at the Institute for Frontier Areas of Psychology and Mental Health at the University of Freiburg
Dr. Marc Wittman researches time perception as an indicator of cognitive functioning and emotion, employing psychophysical experiments, time perception inventories and functional MRI.View full profile ››
Color has an impact on our psychological wellbeing. However, we are often not aware of this effect. The Arousal Theory of Color posits that longer wavelengths, such as red and yellow, are perceived as more activating, whereas colors of shorter wavelengths, such as green and blue, are experienced as more relaxing. For example, when asked to choose a relaxing color, the majority of people opt for blue or green rather than for red or pink, the latter of which have been perceived as energizing, non-relaxing colors. It has been shown that in the extreme, red and yellow colors lead to relatively more nervous, fidgety, and aggressive behavior in man and even in monkeys.1
The Ganzfeld technique consists of exposing a person to an intense homogenous, unstructured sensory field. This type of sensory field can be induced through constant visual and auditory stimulation. For example, through specially designed goggles, one sees a red light and through earphones, one hears “brown” noise, which sounds like a waterfall (see the photo).
Ganzfeld is a German word coined by Gestalt Psychologists at the beginning of the 20th century and means “entire field”.2 We see only red and we hear only a waterfall. The Ganzfeld elicits visual and auditory illusions and it can induce stable—although, in most people, comparably weak—altered states of consciousness. Subjective reports of alterations referring to the visual experience of the Ganzfeld include emerging illusionary percepts, diminishing luminance, the appearance of structures such as moving shapes, and dreamlike imagery with pseudo-hallucinatory quality. Changes in the auditory modality comprise illusionary percepts like sounds of machines, chirping birds or water, and even more complex percepts of voices or music.
One feature of altered states of consciousness during Ganzfeld exposure is an altered sense of time. In general, regardless of the induction method, altered states of consciousness can be characterized by changes in the sense of self and time. Subjective changes in the passage of time during altered states of consciousness have been studied with different induction methods, among which are: hypnosis, meditation, psychedelics, when being absorbed in music or playing video games. In a recent study that used a special Ganzfeld technique where participants sit in an egg-shaped, whole-body perceptual deprivation chamber illuminated with one color, the reported experience of time proved quite distorted.3
In the just-published study with my coworkers Sebastian Kübel and Henrike Fiedler,4 we wanted to compare the experience of time in altered states of consciousness as induced through a 25-minute exposure to a multimodal Ganzfeld with differently colored light (red, green) and brown noise. Sixty-seven participants wore Kasina DeepVision Ganzfeld goggles.
Our results can be summarized in two clusters. On the one hand, we have data on the general effects of the Ganzfeld on states of consciousness; on the other hand, we can interpret our findings in regards to color-specific effects. Relating to the general effects, the more the experience of participants was altered as assessed with a questionnaire, the shorter the participants perceived the duration of the 25-minute Ganzfeld exposure and the faster the subjective passage of time. Such a relative underestimation of duration is a typical sign of altered states of consciousness, e.g., as experienced during deep states of meditation and more generally when people are in flow states while performing activities that they feel positively about. In the green condition, people felt more relaxed after than before the Ganzfeld exposure and this greater relaxation was related to an underestimation of duration and a faster subjective passage of time. In the red condition, in contrast, participants felt more agitated afterward than before. We also found clear effects between the two colors. Participants reported to be significantly more activated in the red condition as compared to the green condition and this greater activation leads to the feeling that the red session had lasted significantly longer than the green session.
Mind-body interventions, such as meditation or yoga, as well as other relaxation techniques, have been introduced into the clinical and health sciences, as I highlighted in a recent blog post at Psychology Today.5 It can be said that the core features of altered states of consciousness act positively against psychiatric symptoms. As we were able to show, a Ganzfeld session has mild properties to induce altered states of consciousness. Especially the green stimulation in combination with brown noise definitely showed to have the potential to become the basis for a new type of relaxation-induction technique, if investigated further.
Independent of these applications, we add knowledge to how green (relaxation) and red (activation) have different effects on us, emotionally and related to the judgment of time.
Note: This post was first published at Psychology Today on 6 October 2020, and can be found here. All rights reserved by the author. Republished with the author’s permission.
Is microdosing LSD safe, and does it really have its alleged benefits? Answering this question requires understanding tolerance to LSD.
“An altered state of consciousness is a temporary change in the overall pattern of subjective experience so that the individual believes that his psychological functions are markedly different from certain general norms of his normal waking consciousness.”
– G.W. Farthing
What do you think of when you hear the phrase “altered state of consciousness”? While they are commonly associated with substance use or the stereotypical Buddhist monk in meditation, altered states of consciousness (ASCs) can arise in a surprisingly wide variety of circumstances.
One of these circumstances is that of exhausting physical activity, which can both train the body and change the mind. This is because alterations in one’s subjective experience reflect not only changes in the brain, but also in other parts of the body. Different forms of movement have their unique characteristics which can facilitate various alterations in one’s consciousness: everything from running to dance to rock climbing and martial arts can produce a unique mental state.
Upon hearing this, one might wonder whether exercise-induced alterations in consciousness are even desirable. Certainly, one is in a kind of “altered state” when in pain at the end of a long workout and only wanting for it to be over. But though all who have ever been forced into gym class know this state of mind, there are other commonly experienced altered states associated with exercise which have more obvious benefits. Some of these – the runner’s high, the “Zone”, and the flow of dancing – are not only enjoyable, but are often associated with an increased motivation to exercise and psychological well-being.1–3
Before I take you through how different types of exercise can affect your state of mind, I have one important message: Exercise-induced ASCs are not reserved for high-level athletes. Everybody who exercises can access them with enough practice and patience. So whether you’re a couch potato or an Olympian, there’s an altered state waiting for you at the end of some good, hard exercise.
“It doesn’t matter how you do it. Just get out there and do it.”
– Dean Karnazes
A runner’s high is basically what it sounds like: feeling amazing during and after running. Scientists have also defined it more precisely: “A runner’s high is a subjective sudden pleasant feeling of euphoria, anxiolysis, sedation, and analgesia after prolonged exercise like long-distance running.“4 Prolonged exercise, in this case, means continuously moving for at least 45 minutes,5 but possibly up to several hours, like in marathons. Similar experiences occur in rowing (“rower’s high”), and they might be linked to the synchrony of movement which is so critical for high performance in rowers’ teams.6 Additionally, both running and rowing involve a specific rhythmic motion and coordinated breathing, which increases focus on the present task. And focus, too, is inherently enjoyable.7
So how does one reach a runner’s high? It likely depends on training status, level of conditioning, and one’s neurobiology. Beginners, for example, may need patience. Experienced runners suggest starting with a moderate running speed as a warm-up, then picking up the pace quickly for a few minutes after the first fatigue sets in. Then comes the hard part: push through any unpleasant sensations as best you can to achieve a consistent pace until you absolutely must slow down (and of course: don’t overdo it). If you feel a sudden surge in energy that drives you to speed up – go with it. After a while, you’ll enjoy a euphoric runner’s high.8
Why does this physical exhaustion in the body create such a pleasant state of mind? Studies in mice show that intense exercise makes the body release endorphins, but endorphins alone can’t explain the runner’s high.21 When released into the blood after intense exercise, they act primarily as local painkillers. They are unable to cross into the brain, and thus cannot induce euphoria.
Instead, researchers posit that runner’s high might be the result of the action of endocannabinoids, which counteract feelings of stress in the brain.5 These molecules are similar to those that make people feel “high” when they smoke cannabis, but your body produces them naturally. And because they are fat-soluble, they can enter the brain, and their concentration in the blood also rises with vigorous exercise.4 A runner’s high, then, might be down to endocannabinoids. In fact, one study found that not only running, but also walking for 45-60 minutes measurably increases endocannabinoid levels. Still, the researchers doubt that a runner’s high can be induced by “just going for a prolonged walk.” They suspect that during prolonged exercise, one eventually reaches a threshold in endocannabinoid levels which must be crossed to reach a runner’s high. And this requires running – not just walking.5
CrossFit is a relatively new training program characterized by “high intensity, constantly varied, functional movements.”9 While running comprises lengthy exercise and repeated cyclical movements, CrossFit is quite the opposite: brief, intense, not cyclical, and much more focused on the variety of weightlifting and functional strength exercises than on conditioning.
Can someone reach an altered state through CrossFit? Approaching this as a sports psychologist, CrossFit athletes of various levels often experience what they call “The Zone.” This refers to the “individual zone of optimal functioning” – when everything comes together perfectly, only the task at hand has the light of attention, and you just go.
According to the sports psychologist and former rugby player Adam Dehaty, who works with CrossFit Athletes’ on their mindsets, the Zone has eight characteristics:10
This zone of optimal functioning is mainly determined by the balance of challenge and ability. When someone’s ability to deal with a challenge is too low, they will be overwhelmed and likely fail. The reverse is also true: when something is not challenging enough, people get bored and don’t perform at their best. The Zone is the happy medium: a challenging, but not overwhelming balance between task difficulty and individual ability. This is what makes The Zone an individual zone of optimal functioning. And indeed, it is not unique to CrossFit. The Zone is a type of flow state, in which someone is fully immersed in an activity with an enjoyable, energized focus.7 Although CrossFit culture particularly emphasizes it, one can be “in the zone” during practically any type of exercise – or indeed, any challenging enough task.
With the right mindset and a well-calibrated task difficulty, entering The Zone just happens ― if you are prepared. In CrossFit, this state partially stems from a strong commitment to reaching a goal with a rigorously planned workout: Counting repetitions, focusing on the movement in the moment, and anticipating what comes next to make a smooth transition from one task to another. All of this creates a feeling of a painless flow and performance with perfect technique, which saves energy and breath. Alison Moyer, a CrossFit coach, bodybuilder, and athlete from Pennsylvania, sums it up:
„So many times in CrossFit, I’m in tune with the pain – with the shortness of my breath, the difficulty of movement, the tightness in my limbs. But then, every once in a while, I discover those rare moments … that make me feel unstoppable, unbeatable. I’m aware of what I’m doing, and aware that I’m moving, but I’ve found the place right beneath my redline where my body just takes over and goes. It doesn’t matter that I’m tired, that my mouth is dry, that I can’t breathe, or that my legs are going numb. … that feeling, the incredibly superhuman sensation, is what keeps me coming back for more.“11
Many CrossFit athletes strive for exactly this feeling of painless, concentrated flow during a workout. After all, the intense workouts like CrossFit aren’t only about what happens in the body, but also in the mind.
“When a body moves, it’s the most revealing thing. Dance for a minute, and I’ll tell you who you are.”
– Mikhail Baryshnikov, Ballet Dancer
Dance movement therapy has been investigated as an adjunctive clinical practice in psychiatry and neurology,12–14 yet therapists by no means invented it. Trance and shamanic dances have been used for thousands of years in different cultures all around the world, and they are still practiced by many, such as the Sufi Dervishes.15
Of course, the purpose of dance-related sports is very different from trance dance and therapeutic dancing, but they all share the connection between the dancer’s internal state and the outer, visual performance. Perfecting both is crucial in professional dancing. One beautiful example is the Olympic gold medal performance in pairs free figure skating by A. Savchenko and B. Massot in 2018.
Music on its own is certainly a powerful inducer of altered states, but the movement of dancing adds another element to it. Music leads through rhythm and style. Dancing then, means to translate rhythm and style into a flow of movement. The synergy between music and movement can create a state of flow in which people not only forget about time and their surroundings, but also feel more connected to themselves:
“Music and beats are like a lighter that is switched on: the warmth and the brightness expand in my whole body: my head moves, my body moves, my mind moves. When I dance, all of me starts melting into the sound, thoughts disappear. I feel like being out of the system, out of time and out of space. I am in my own and I feel myself in every single cell of my body.”
–Anna, from Cologne
To enter such a state, one need only to be able to immerse oneself in the feeling of rhythm, move in different ways, and concentrate. Professional dance skills are not required – nor, even, is any particular talent! Altered states from dancing arise independently of how the dance appears to other people.
Dance is unique because many of us gravitate toward it automatically. When people hear music they like – and sometimes even music they don’t – they almost unconsciously try to connect to it. They start to tap their feet, bop their heads, move their hips, or whatever spontaneous movements seem to feel right (and are socially appropriate in the current setting, of course).
Altered states in dance involve fully surrendering to this urge to move, or mastering an intentional intentional dance routine. When fully immersed in the dance, we can begin to feel so connected to the music that we lose everything else. People lost in dance feel liberated, often stress-free, and even like they are one with the rhythm, their surroundings, and other dancers. They may lose track of time and dance for much longer than they expected. This is nearly the definition of an altered state: at its most extreme, the mind is filled with nothing but dance. Like The Zone, it is another species of flow. It is an intrinsically rewarding state, and dancers who experience flow will seek it again and again.16
Whether you call it “The Zone,” a certain “high,” “flow,” or something else: physical exercise and movement – especially in combination with an open but focused mindset – can induce an altered state of consciousness which may come both during and after the exercise. These altered states share movement as their basis, as well as the experience of an intrinsically rewarding state of mind.
Movement is one of our basic needs and it is crucial for a healthy mind and body, as well as a healthy connection between them.2 Because physical exercise and movement have the potential for enhancing valuable states of consciousness, we can easily see them as part of a culture of consciousness – a Bewusstseinskultur. Physical exercise both decreases and prevents suffering, creating a valuable state of consciousness which may even enhance our capacity to live well and connect to other people. In turn, healthier relationships with others can lead to further valuable states of consciousness and reciprocal, enriching relationships.
As a sports psychologist, here’s my advice: If you’re feeling down, especially when you’re not sure why, it won’t hurt to move. If you are stressed or overwhelmed, focusing on moving can pull you out of that mindset, allowing you to return to your challenges later with a refreshed brain. If you are feeling lonely, movement may boost your mood – especially if you can find others who share that interest. If you are really suffering mentally, you may need to see a mental health care professional – but still don’t forget to move, because it is one of many things that might help.2,22
Movement is not the ultimate solution for everything, but I suggest that natural movements and their potential to increase the awareness and knowledge of one’s body should be cultivated in everyone’s life. Integrating movement into psychotherapeutic treatment plans may even create additional benefit beyond psychotherapy and medication.22 Furthermore, a culture that values movement and valuable states of mind has the potential to prevent mental and bodily suffering in children, youths, and adults.
It does not matter what kind of physical exercise you do. Just move. Consciously.
Is microdosing LSD safe, and does it really have its alleged benefits? Answering this question requires understanding tolerance to LSD.
Crucially, while not all humans will have the experience of being pregnant or carrying a baby, the experience of being carried and growing within another person’s body is universal.
Imagine you are walking on warm sand, on a sunny summer’s day, holding hands with your partner. While perceiving this environment, your brain receives and needs to integrate a cascade of sensory information coming from both outside and inside your body: the warmth of the sand, the brightness of the sunlight, the salty smell of the air, the sound of your heart pounding in your chest, the warmth of your partner’s skin touching your hand.
We usually experience a ‘real me’ that is linked to the body and which lies at the core of all of our sensory experiences, emotions, memories, and thoughts. This ‘I’ or ‘me’ is somehow always there, even if only in the background – transparently, so to speak; and it is felt as being distinct from the world and other people (the sand and your partner, let’s say).
This sense of being a ‘real me’ connected with a real world ‘out there’ makes us feel present and immersed in the flow of our daily lives. But how exactly does this work?
In a seminal paper entitled ‘Whatever next? Predictive brains, situated agents, and the future of cognitive science’, Andy Clark1 proposed that the brain’s job is to predict whatever information is coming next based on the information perceived before. Instead of being a passive sponge receiving information from inside and outside our bodies, the brain actively anticipates the world through the lens of past experiences. Whatever we have perceived and experienced before leaves traces, so to speak, in our nervous and perceptual systems. The brain uses these ‘traces’ prevailingly to spot danger. This is why it’s so difficult to forget negative events: the brain wants to keep us out of trouble. Harmless information, like the colour of the doorknob at my hotel, will likely be treated as boring and erased from memory. However, the colour of the jacket on the thief that attacked me on the street stays with me. This is an important insight stressed by Clark and other researchers like Karl Friston2 and Jakob Hohwy.3
Let’s have a closer look at the influential expression “whatever next”. Indeed, what really matters for our survival is to correctly perceive not only what happens next, but also what happens here, that is, next to my body. Take the following example.
Suppose I’m drinking a cup of coffee on a terrace on a Greek island (oh, well – I’m allowed to dream, I guess, since terraces are currently closed in my country). But let’s imagine the scene: I take a sip and next want to admire the clouds above, but while directing my attention to the sky, I see a spider on the table close to my hand. Suddenly, the perception of what is next to my hand is a high priority. Temporally speaking, both the perception of the sky and of the spider come ‘next’, that is, after me sipping coffee. But the perception of the spider next to my hand puts my defence system on red alert. Now I don’t care about the beauty of the sky anymore, or the taste of my coffee. Now, all my perceptions and thoughts and emotions are clustered around one single important fact: the spider-next-to-my-hand, and how to escape safely.
Why is this observation important?
It is important because philosophers and scientists across disciplines and traditions have focused mainly on vision and distal perception: I see the world / an apple / a red tomato ‘there’. In reality however, our perceptions are proximal and multisensory in nature.4 We constantly perceive the world and what is next to our body through our skin, for example, or through smell. However, although these ‘modest’ senses give us the most essential information about our survival, we tend to neglect them, dismiss them, or take them for granted.
We typically realise how important things are only when we lose them. For example, with the current health crisis provoked by the COVID-19 virus, many of us temporarily lost our sense of smell. People are starting to realise how important this proximal sense was to one’s sense of self and sense of presence in the world.5
Paradoxically, precisely because proximal senses such as touch and smell are so close or ‘next’ to our body, we typically underestimate their importance to us. Amongst these proximal senses, which are blended to form an almost transparent experiential background, tactile experiences have a special status in orchestrating our lives. 18 I can see at least two main reasons for that.
First, touch is mediated by the skin, the oldest and broadest organ in terms of size and function.6,7 This means that the most primitive way to meet and perceive the world around us is via touch. It gives us the most fundamental sense of presence, of reality. Recall the famous Saint Thomas anecdote: in order to believe that a wound was real on the other’s body, he felt the need to touch it. Seeing it alone was not enough.
The skin also mediates the boundary between the self and the outer world. At the same time, it distinguishes us from and relates us to the reality ‘out there’. Tactile experiences have what the French philosopher Maurice Merleau-Ponty called the inevitable duality ‘touchant/touché’: I can see someone without being seen back, but I cannot touch an object or a person without being touched back. Inevitably, by holding hands with my partner, I receive information not only about my hand, but his hand too (his skin is warm and my skin is cold, for example). This inescapable duality encouraged researchers to look at the skin as being a relational organ par excellence.8
Second and importantly, touch plays a key role in exploration and social bonding, which confers a sense of closeness and belonging.
One important yet overlooked aspect of the current debates on the nature of perception is that our most primitive perceptual experiences emerge within the body of another person. In other words, the most primitive embodiment is a shared embodiment, or co-embodiment.9 Crucially, while not all humans will have the experience of being pregnant or carrying a baby, the experience of being carried and growing within another person’s body is universal.
This means that our most primitive experiences may be fundamentally shared experiences.10,11,12,13 Indeed, well before we meet other people’s minds, we literally meet their bodies – and depend on them for survival. Remember, for the brain, survival is key. Living organisms like ourselves have an inescapable drive to live on and potentially reproduce. Humans come into the world within another’s body and initially remain dependent on the physical closeness and affection of a caregiver for survival and happiness.
The observation that humans come into the world within another’s body could have two important implications for critical questions fuelling current debates on the nature of perceptual experiences, consciousness, and self-awareness.14
First, a dynamic and complex system such as the human body needs to be able to play a double game in order to survive and potentially reproduce. On the one hand, it has to successfully maintain sensory states within certain physiological bounds: if we get too cold or too hot for too long, we die. On the other hand, the body must flexibly change these states in order to adapt to a constantly changing environment.15
If we look at the human body through this dynamic lens, it become obvious that what happens in between the organism and its environment – the boundaries – plays a key role in making sure this game is played successfully and flexibly enough to keep the organism alive. Future work on perception and consciousness thus needs to define the critical notion of “boundary” or “in between”: in other words, the process of exchanges between two states or two organisms.
The notion of a ‘Markov blanket’ has been recently advocated as a promising way to conceptualize a boundary mediating the interactions between a system and its environment.16 A Markov blanket can be roughly described as a statistical boundary that separates two sets of states. One seminal example is the cellular membrane separating intracellular and extracellular dynamics. The boundary not only separates the system from its environment, but also inherently relates the system to its environment.
A second key implication resulting from our embodied emergence concerns consciousness itself, and the very definition of the term ‘minimal self’ (Ciaunica, forthcoming). Previous approaches have addressed this question by trying to find the fundamental basis of minimal selfhood.14,17 Yet another alternative is to focus on how selfhood and conscious experiences emerge and dynamically unfold across one’s lifespan. To use a metaphor, ‘minimal’ in this sense would refer to the seed that contains all the latent information about the upcoming tree, rather than the schematized and abstract structure and shape of a fully-fledged adult tree.
And if we look at how the ‘human tree’ gets off the ground (so to speak) in utero, then we simply can’t ignore its bodily and relational roots.
The same way one cannot understand what a tree is and how it functions by looking at its visible components only – branches, leaves, trunk – and ignoring its invisible roots, one cannot understand our conscious experiential life without considering its invisible basis: its bodily shared roots.
The Psychedelic Compendium is a series of curated lists of research articles introducing specific topics in a nutshell. Since psychedelic research is a rapidly growing field and new articles are published almost daily, we understand that it might be overwhelming to skim through a multitude of publications searching for the right one. To make it easier to find relevant research, we are introducing lists of article recommendations carefully selected by our team.
Comprised of both open and closed access articles, our lists of recommended readings aim to lay the foundations for understanding distinct aspects of psychedelic research. Starting from basic overviews and then diving deeper into specific research perspectives, the lists highlight the most important publications in the field.
To make the lists a handy tool for not only researchers and professionals but also journalists and the general public, we will provide a brief summary of each article. We believe that bridging the information flow between academia and society will significantly benefit both parties. High quality research combined with clear channels of communication with the public will facilitate responsible policy making and therefore result in sustainable development of the relations between science, governments, and the population.
This post will be continually updated – stay tuned for the incoming recommendation lists!
These ten articles will give you a solid foundation to start your psychedelic research journey. You will gain an overview of state-of-the-art of psychedelic research, the history of psychedelic exploration, the many applications of psychedelic substances in various fields, and most importantly, their therapeutic potential.
Psychedelic-assisted therapy has the potential to help improve global mental health. In this list, we will introduce the history and current state of the research on psychedelic-assisted therapy, as well as challenges and future perspectives.
Psychedelics offer a new avenue in the treatment of mood disorders. In this list, we will explore the advantages of psychedelics over mainstream antidepressants and summarize essential studies investigating the potential of psychedelics in the treatment of depression and anxiety.
This list of recommended readings explores the diversity among serotonin receptors, the history of their discovery, their relations with psychedelics, and their mechanisms of mediating subjective experiences and therapeutic effects.
In this list, we focus on general press articles about psilocybin research and therapy that were published mainly in larger international newspaper outlets.
This list of Top 10 Articles of 2020 will discuss a ground-breaking trial with psilocybin for major depressive disorder, long-term outcomes of MDMA-assisted psychotherapy for PTSD, how psychedelics work in the brain, and how to produce psychedelics at a larger scale.
This selection of research articles on ketamine for mental health will explore its promise in treating not only depression but also the positive effects on suicidal ideation, addiction, and further symptoms of mental health disorders.
This list presents press articles discussing the therapeutic use of ketamine in mental health treatments and its potential modes of action.
The growing field of social interoception—which examines how social emotions arise from subjective appraisal of bodily states—calls for a rebranding of mental health issues as “social health issues” and builds the case for new forms of embodied social treatment, including psychedelic-assisted therapy. I spoke with researchers at UC San Diego, the University of Utah’s Social Development Lab, and the University of Zurich to find out more.
It was by studying a part of the brain called the insula that neuroscientist John Allmann first realized self-awareness and social awareness are part of the same functioning1. Tucked deep within the Sylvian fissure, a connectivity hub disguised as an island unto itself, the insula is one of the main brain structures responsible for translating body states into social emotions. It starts doing this for us the moment we are born, recasting intimate touch into feelings of pleasure or a harsh tone from a parent into feelings of shame. If we do not receive appropriate care as children, the way the insula encodes the relationship between our bodies and social emotions can cement in a maladaptive way, leading to a propensity for mental health issues later in life2. Mounting evidence shows that it may be possible to change this relationship, since the insula also plays a role in therapeutic practices like mindfulness meditation, body trusting, and psychedelic-assisted therapy. Taken together, these findings suggest that the link between body, self, and social emotions plays a bigger part in mental health than we might think, highlighting a need for more forms of therapy which directly target social emotions through the body.
The insula’s main function—helping us recognize what we are experiencing based on what we sense—is called interoception. It allows us to interpret an “empty stomach” as physical hunger or “butterflies” as excitement or fear. As mentioned above, social emotions arise from this process. Despite the connection between interoception and social emotions, little scientific attention has been given to the social origins of interoception.
At the University of Utah’s Social Development Lab, Kristina Oldroyd’s pioneering work suggests that early social experiences significantly impact areas of the brain responsible for interoception by influencing the development of the bodily self. Oldroyd’s research team has found that insensitive caregiving—which includes responding inconsistently to a child’s needs or rejecting distress altogether—can impair a child’s ability to form accurate representations of bodily sensations3. For example, when a child who is learning to walk falls down and feels physical pain, a sensitive response from a parent might be, “That must have hurt,” whereas an insensitive response would be, “You’re fine, that didn’t hurt, get back up.” For the child to become comfortable detecting, acknowledging, and expressing bodily cues, the parent must notice what the child is experiencing, draw joint attention to it, and label it3:
“To the extent that caregivers recognize, honor, and respect their children’s bodily experiences, the child will develop more accurate interoception,” Olroyd explains. “To the extent that a child’s bodily experiences are denied, devalued, ignored, or punished by parents, the child will find ways to avoid feeling them, and develop a distorted sense of interoception.”3
Oldroyd maintains that the way we learn to regulate physical pain is no different from the way we learn to regulate emotional pain—in both cases, we are socialized through our bodily experience. Neuroscientific studies support her theory, showing that children who are classified as having anxious or avoidant attachment styles have markedly lower insular volume than securely attached children4. If the bodily self remains unchanged throughout those children’s adult lives, when relationships become more complex and social-emotional regulation increasingly important, Oldroyd believes it is poor interoception itself which may lead to disorders like anxiety, depression, and addiction. It may also lead some of us farther away from social connection when, ironically, that may be what we need the most.
“One idea I’m working with,” says Andy Arnold, a psychologist and interoception expert at the University of California San Diego and Visiting Professor at Knox College, “is that interoception might be a critical mechanism for evaluating needed resources in our lives. If interoceptive understanding is turned down, then one might not be able to accurately sense the lack of needed resources [like] social connection and act accordingly.” For example, addiction could be a misevaluation of resources where you “overevaluate the drug but underevaluate other stimuli in your life,” Arnold told me, adding that the insula probably plays a critical role in this process.
It also works the other way around: substance abuse disrupts interoception and damages the insula. Brain images of people with alcohol use disorder show significantly reduced grey matter in the insula, marked by a profound loss of von Economo neurons (or “empathy cells”)5, a relatively recent evolutionary specialization in humans thought to be crucial for interoceptive sensitivity and prosocial behavior6. Paradoxically, in certain cases, damage to the insula actually reverses addictive behaviors. In a 2015 study on addiction, researchers at the University of Southern California observed: “On the one hand, alcohol dependence damages the insula. On the other hand, damage done to the insula reduces cravings for alcohol.”7
But this is not a contradiction if you view addiction as social health issue. The insula might normally motivate us to seek social reward, but if we cannot understand our social-emotional needs based on what we are feeling, we might turn to substances to resolve this uncertainty. Heavy substance use may be like putting the wrong type of fuel in the tank: when the brain and body crave social connection, giving it something else harms the engine over time although it appears to run fine. In this case, perhaps the habitual relationship with the drug outlasts the original motivation to use it. On the other hand, damaging the insula outright may destroy its record of the substance as a substitute for social reward, and therefore immediately reduce one’s craving for it.
The insula shows us just how misguided we may be in labeling disorders like addiction, anxiety, depression, and substance abuse as “mental health” issues. If interoception initially develops in the context of interpersonal relationships, then so do many of our afflictions—and so, too, should our treatments.
In November 2019, Arnold and his colleague, neuroscientist Karen Dobkins, published the first academic discussion of what they call “social interoception,” arguing that interoceptive ability facilitates social connection8. To understand how interoception might work in a social situation, imagine an encounter that raises one’s heart rate—a response meant to enhance alertness and prepare one for “fight or flight.” Dobkins and Arnold believe it may not be one’s physiological response per se that causes social stress, but rather one’s subjective interpretation of it. They reference a series of studies by researchers in Munich who used social stress tests designed around impromptu public speaking9 and social exclusion10 in a game setting to measure interoception. The researchers found that people with higher interoceptive accuracy reported fewer negative emotions after the challenging social situation, despite their heart rate and skin conductance being similar to participants with lower interoceptive accuracy. In other words, two people can have the same internal body state but experience completely different levels of social discomfort.
“This leads to the interesting idea that perhaps greater interoceptive accuracy allows one to identify the physiological response as resulting from an objective, external ‘social situation’ rather than an attribute of oneself,” Dobkins and Arnold say. “This could reflect better emotional regulation in social situations.” Oldroyd echoes these ideas in her own work: “It is the bias to interpret bodily signals in a negative manner, rather than the noticing of bodily signals, that contributes to both the cognitive and behavioral symptoms of anxiety.”
There is an important subtext to these statements: Maybe we are not born with our various social neuroses. Maybe we are born with a bias towards positive social signals, towards bonding with others. Poor interoception, often developed in the context of an adverse childhood, may be what shifts the bias towards negative signals. The way to shift it back, Dobkins says, would be to start listening to and trusting your body before your mind jumps to conclusions. In their own work on loneliness, Dobkins and Arnold found that one measure of interoception in particular—body trusting—predicted variations of subjective loneliness amongst university students at UCLA11, suggesting that connecting with your body allows you to connect with others, whether that means making more friends or different friends. The more you trust your own body, the better you become not only at reading yourself but at reading and connecting with other people.
“You know the feeling when you and another are ‘on the same page’?” Dobkins says. “Well, that’s not what I am talking about. That’s the mind reporting back and saying that, ‘the other person and I believe or want the same thing.’ Connection is body-based. It’s a knowing in the body. Which means you need to know your body.”
The growing field of social interoception may help us better understand and treat not only loneliness but anxiety, addiction, eating disorders, depression, and other conditions traditionally associated with thought patterns rather than body signals. In fact, social interoception may be a key piece in the puzzle of explaining how psychedelic-assisted therapy functions.
As part of the Salience Network, one of the main functions of the insula is to orchestrate activity between other networks, including the Default Mode Network and the Central Executive Network. In 2017, Robin Carhart-Harris and his research team at Imperial College London found hypo-connectivity of the insula to be “a neurobiological signature of the MDMA experience,” correlating it with reduced anxiety, altered bodily sensations, and changes in interoception12. “Further understanding of how MDMA affects the insula,” Carhart-Harris writes, “might be crucial to elucidating the neurobiological underpinnings of re-emerging interest in MDMA as a therapeutic adjunct to psychotherapy in the treatment of anxiety disorders including PTSD.” Other teams have found similar results, linking insula hypo-connectivity to the LSD experience13.
Research on the neural correlates of different types of mindfulness meditation points to the insula and the body as well. Commenting on a study on Loving Kindness, Focused Attention, Open Monitoring, and Mantra Recitation, Carhart-Harris notes that although these four meditation styles are clearly dissociated by their neural correlates, there are “a few recurrent patterns of activity modulation, in particular in the insula, an important multisensory area heavily involved in interoceptive awareness”14. He suggests that involvement of the insula in all four styles of meditation points towards “the central role of the attentional control of bodily awareness, and awareness of breathing in particular, during various contemplative practices.” As we’ve seen, body awareness is closely linked to social emotion, which may help explain the benefits of both mindfulness meditation and psychedelic therapy.
At the University of Zurich, Katrin Preller studies the social health benefits of psychedelics. Her work in this area confirms Allmann’s notion that how we see ourselves is inextricably intertwined with social perception. For example, psilocybin and LSD have been found to reduce social pain specifically through alterations in self-processing15, which include experiences of unity and connectedness.
“One of the main aspects of the psychedelic experience is the sense of connectedness – with the universe, nature, but importantly also with the social environment,” Preller told me. “Furthermore, we see an increase in emotional empathy which may be an important factor contributing to the feeling of connectedness. In clinical trials, we are currently testing the hypothesis that this experience contributes to the efficacy of psychedelic-assisted therapy.”
In a successful series of Johns Hopkins studies targeting psilocybin and nicotine addiction, participants “identified social factors, i.e., smoking as a way of connecting with other people, that contributed to their addiction.” 16 They reported psilocybin-induced feelings of love and connection with their environment and other people, independent of smoking as a social factor, as important for quitting smoking17. “Psilocybin may have re-instated social reward processing, helping patients to overcome their addiction,” Preller speculates. “My hope is that therapy will focus more on social cognition and the social environment of patients. For example, social trainings may aim at re-instating social reward processing in addicted patients, helping them to re-connect with their social environment.”
Research on the insula and social interoception suggest that the body is the main channel through which these changes must occur. Feelings of love and connection are exactly that—feelings. It seems we must feel the social reward, hold it in our bodies, to stop needing its replacement. In doing so, maybe we restore some kind of default setting. For all we know, “connectedness” may not be an additive feeling at all. On the contrary, it may be the stripped-down, primordial sensation that the self is socially constructed. And while it may be a new feeling to the psyche, Oldroyd’s work suggests it is not a new feeling to the body. Perhaps this is why psychedelic experiences can feel so profound to some: deep in their bodies, they’ve always known.
In April 2019, researchers at Johns Hopkins University published an animal study showing that MDMA reopens a “critical period” when the mouse brain is sensitive to learning the reward value of social behaviors18. Although it is a neurobiological study, attributing the reopening to heightened, oxytocin-induced brain plasticity, the behavioral mechanism sounds very much like Oldroyd’s childhood theory of interoception: Critical periods were first described in snow geese in the 1930s when goslings were found to bond with an object if their mother disappeared 24 hours after they hatched, but not 48 hours after they hatched. You can imagine which goslings would be best able to socialize their bodily cues going into adulthood, assuming geese are self-aware enough to do so. In the Hopkins study, adult mice who were given MDMA showed prosocial behavior in a way normally seen only in juveniles, forming positive associations between companionship and a certain type of bedding in their enclosure. Neuroscientist Gül Dölen and her team found that this happened only if the drug was given to mice when they were with other mice, not if it was given to mice while they are alone. “This suggests that reopening the critical period using MDMA may depend on whether the animals are in a social setting,” Dölen says.
Although Dölen suggests this kind of treatment may work in humans by strengthening the psychotherapist-patient bond, I would argue it is also a case for a different type of therapy altogether—something along the lines of social embodied therapy, or group bodywork led by psychotherapists. Social reward learning occurs through the body, in a social setting, in large part because we are socialized through our bodies early in our lives. If the therapeutic aim is adaptive social connection, then why not place a greater emphasis on connection as therapy?
Indeed, it seems questionable that any of us should heal as isolated subjects, when we are born to bond, and when the rest of our lives are built around connection. No matter how great your relationship is with your therapist, the dynamic is often that of an object being scrutinized under a microscope. Modern therapy still whiffs of stigmatization and quarantine—our problems so private that they must be kept a secret. Even Somatic Experiencing therapy, which at least reveals these problems to us through the body, largely treats each person in isolation. We do not necessarily have to share our problems to heal. In fact, some PTSD patients become asymptomatic after psychedelic assisted therapy sessions where no words are exchanged19. But it may be the case that we can only re-open the doorways of social learning—and heal from social illnesses—through the body, through each other, and through the part of the brain that so ironically appears to stand alone.
1. Chen, I (2009). Brain Cells for Socializing. Smithsonian Magazine.
2. Khalsa S et al (2018). Interoception and mental health: a roadmap. Biological Psychiatry. 10:004. doi: https://doi.org/10.1016/j.bpsc.2017.12.004
3. Oldroyd K, Pasupathi M and Wainryb C (2019). Social Antecedents to the Development of Interoception: Attachment Related Processes Are Associated With Interoception. Psychol. 10:712. doi: 10.3389/fpsyg.2019.00712
4. Lim L, Radua J, Rubia K (2014). Gray matter abnormalities in childhood maltreatment: a voxel-wise meta-analysis. J. Psychiatry 171 854–863. 10.1176/appi.ajp.2014.13101427
5. Senatorov V-V, Damadzic R, Mann C-L, Schwandt M-L, George D-T, Hommer D-W, Heilig M, Momenan R (2015). Reduced anterior insula, enlarged amygdala in alcoholism and associated depleted von Economo neurons. Brain, 10:305. doi: https://doi.org/10.1093/brain/awu305
6. Yang L, Yang Y, Yuan J, Sun Y, Dai J, Su B (2019). Transcriptomic Landscape of von Economo Neurons in Human Anterior Cingulate Cortex Revealed by Microdissected-Cell RNA Sequencing. Cerebral Cortex. 29, 2, 838–851. doi: https://doi.org/10.1093/cercor/bhy286.
7. Droutman V, Read S-J, Bechara A (2015). Revisiting the role of the insula in addiction. Trends in Cognitive Neuroscience. 10:005. doi: https://doi.org/10.1016/j.tics.2015.05.005
8. Arnold AJ, Winkielman P and Dobkins K (2019). Interoception and Social Connection. Psychol. 10:2589. doi: 10.3389/fpsyg.2019.02589
9. Werner N. S., Duschek S., Mattern M., Schandry R. (2009). Interoceptive sensitivity modulates anxiety during public speaking. Psychophysiol. 23 85–94. 10.1027/0269-8803.23.2.85
10. Werner N. S., Kerschreiter R., Kindermann N. K., Duschek S. (2013). Interoceptive awareness as a moderator of affective responses to social exclusion. Psychophysiol. 27 39–50. 10.1027/0269-8803/a000086
11. Arnold AJ, Dobkins K (2019). Trust Some Body: Loneliness is Associated with Altered Interoceptive Sensibility [Abstract and Poster]. Emotion Preconference for Society for Personality & Social Psychology, Portland, Oregon.
12. Walpola, I, Nest T, Roseman L, et al (2017). Altered Insula Connectivity under MDMA. 42, 2152–2162. doi: 10.1038/npp.2017.35
13. Preller et al (2019). Changes in global and thalamic brain connectivity in LSD-induced altered states of consciousness are attributable to the 5-HT2A receptor. doi: 10.7554/eLife.35082
14. Millière R, Carhart-Harris RL, Roseman L, Trautwein F-M and Berkovich-Ohana A (2018). Psychedelics, Meditation, and Self-Consciousness. Psychol. 9:1475. doi: 10.3389/fpsyg.2018.01475
15. Preller KH, Schilbach L, Pokorny T, Flemming J, Seifritz E and Vollenweider FX (2018). Role of the 5-HT2A Receptor in Self- and Other-Initiated Social Interaction in Lysergic Acid Diethylamide-Induced States: A Pharmacological fMRI Study. Journal of Neuroscience. 38 (14) 3603-3611. doi: 1523/JNEUROSCI.1939-17.2018
16. Noorani T, Garcia-Romeu A, Swift TC, Griffiths RR, Johnson MW (2018). Psychedelic therapy for smoking cessation: qualitative analysis of participant accounts. J Psychopharmacol. 32:756–69. doi: 10.1177/0269881118780612
17. Preller KH and Vollenweider FX (2019) Modulation of Social Cognition via Hallucinogens and “Entactogens”. Psychiatry 10:881. doi: 10.3389/fpsyt.2019.00881https://doi.org/10.1038/s41586-019-1075-9
18. Nardou R, Lewis EM, Rothhaas R. et al. (2019). Oxytocin-dependent reopening of a social reward learning critical period with MDMA. Nature 569, 116–120.
19. The Tim Ferriss Show Transcripts: Marcela Ot’alora—How to Become a Psychedelic Therapist (#396): https://tim.blog/2019/11/25/marcela-otalora-transcript/
This blogpost discusses research that is featured on MIND’s ASC Study Monitor, a curated, freely accessible, and regularly updated database of scholarly publications concerning altered states of consciousness (ASCs). This interview is the first of its kind in the MIND blog, in which we identify interesting studies through our work on the ASC Monitor, and arrange to interview the authors to discuss their motivation, background and general attitudes towards psychedelic science. The paper discussed in this interview is:
Yanakieva, S., Polychroni, N., Family, N., Williams, L. T. J., Luke, D. P., & Terhune, D. B. (2019). The effects of microdose LSD on time perception: A randomised, double-blind, placebo-controlled trial. Psychopharmacology, 236(4), 1159–1170. https://doi.org/10.1007/s00213-018-5119-x
Lukas: Could you tell me what it was that drove you to study altered states of awareness, like synesthesia, hypnosis, or the psychedelic experience?
Devin: I think the starting point is that I became interested in hallucinations during my undergraduate, particularly in non-clinical populations. Then I was fortunate enough to take a course on hypnosis by a really excellent person, Jean-Roch Laurence1. So then I studied suggestion and hallucinations during my Master’s and then my PhD was focused on the cognitive neuroscience of hypnosis. I was always interested in various other aspects of altered states and anomalous experiences, so I did a little bit of synesthesia research during my PhD. Then I became a research fellow in Oxford and the focus there was on hypnosis and synesthesia, but I was always very interested in time perception. I feel that time perception is a really fundamental feature of conscious experience.
So, I did my undergrad in philosophy and one of my absolute favorite philosophers was Martin Heidegger. Heidegger wrote, in my opinion, one of the most brilliant philosophical texts ever, “Being and Time”, in which he basically makes a really fundamental series of arguments on how critical time is for human experience. That was something that always kind of stuck with me, and when I was doing my postdoctoral research fellowship, I started doing more time perception and moved away from synesthesia research a bit.
I became interested in psychedelics primarily through my interest in synesthesia. Later I was contacted by the group that was running this microdosing study about being a consultant on a certain feature of the study. I asked them if there was any opportunity to include a time perception task directly inspired by this nice classic study by Marc Wittmann4, which showed that psilocybin led to a tendency for people to under-reproduce temporal intervals in a temporal reproduction task. So that was the origins of this particular study and that’s kind of how it all came together.
L: Perfect. Could you give our readers a short summary of the study, and explain your main findings?
D: Sure! So, based on Marc’s2 data, we had fairly good evidence that psilocybin leads to under-reproduction of temporal intervals, particularly longer ones, but we were interested in whether that effect would still be present with microdosing.
So specifically, we were interested in the question of whether the effects of psilocybin in Marc’s study are attributable to the direct neurochemical effect on time perception versus psilocybin triggering various types of altered states of consciousness that then have an indirect or a subsequent carryover effect on time perception. Basically, the question is if the neurochemical effects are sufficiently strong to elicit a change in your perception of time even though it doesn’t actually produce altered states of consciousness.
In the study we had 48 participants, they were elderly individuals so that’s an important kind of confound that needs to be acknowledged. There was a placebo condition and 3 microdose conditions of 5, 10, and 20 micrograms of LSD. So when the participants completed the task, we also had them complete self-report measures of various types of subjective states. The ones that we looked at were whether they felt any kind of drug effects, any perceptual distortions, any unusual thoughts, any experience of feeling high, and whether they felt a change in attention.
What our results seem to suggest is that the participants had a sense of feeling a little bit different – like they’re picking up on something. But they didn’t have perceptual distortions or unusual thoughts, they didn’t really feel high per se, and they didn’t really notice any changes in their attention. Based on this, it appears pretty clear that there’s no kind of pronounced altered state of consciousness under microdosing.
Then the principal result we looked at for the temporary production task was median reproduction times. So basically, how long the participants would hold down the space bar after encoding a stimulus interval of a circle that’s presented on the screen. That gives us an idea about the extent they’re under-reproducing or over-reproducing which in turn can provide us with an indirect measure of the extent to which they’re underestimating or overestimating the stimulus interval. We used a wide range of intervals from 800 to 4,000 milliseconds. Marc Wittman in his study only found effects for in the range of about 4,000 milliseconds onwards. We found that when you compare the three LSD conditions versus the placebo, the participants would over-reproduce the intervals. So they would hold down the space bar longer when completing this task than the participants in the placebo condition.
Interestingly enough, the effect was only present for 2,000 milliseconds onwards. Now, there’s a number of different ways of interpreting these data and I should say that I’m not firmly committed to any particular interpretation given that it’s early days in our understanding of these effects. In the paper we briefly entertained a number of possibilities and suggested that given how far after they had received the dose it might be a late-phase dopaminergic effect. This idea is based on animal studies that suggest that there’s an early phase where LSD functions as a serotonin agonist and then a later phase where it functions as a dopamine agonist. We were never completely satisfied with that interpretation, however.
As I’ve thought about these data a bit more, I’ve begun to think that these results might be better understood within the context of Bayesian models of interval timing. Essentially, these models stipulate that our perception of time arises from sensory information regarding a stimulus that is shaped in part by priors, which we form from the statistics of our environment. The extent to which the prior influences our perception is referred to as “prior weighting”. Prior weighting or de-weighting will be greater in certain individuals or may differ across contexts, psychedelic states, and so on.
Prior weighting, more generally, provides an elegant explanation about how our expectations can often shape our perception. Applied to temporal reproduction tasks, the prior would be the mean stimulus interval. An interesting consequence of prior weighting is that longer stimulus intervals are under-reproduced because the prior draws the reproduction time closer to the mean whereas shorter intervals are over-reproduced, again, drawn closer to the mean. This account provides a very nice explanation of a classic effect in the time perception literature: Vierhordt’s law, which is that we tend to over-reproduce shorter intervals and under-reproduce longer intervals. If we apply this type of account to our data, a simple interpretation is that microdosing produced a tendency to down-weight priors, that is, reduce their influence. This then led participants to over-reproduce long intervals. That may also explain why the effect is restricted to the longer intervals.
If this interpretation is true, microdosing should have also led to under-reproduction of the shorter intervals. Interestingly, there was a very weak tendency for this to occur although it was nowhere near statistical significance. What makes this interpretation even more interesting is that it aligns very nicely with a recent model of psychedelics by Carhart-Harris and Friston, which proposes that psychedelics produce a down-weighting of high-level priors3. For anyone that is interested, I presented this newer interpretation of our data at Breaking Convention in August.
L: You already mentioned Marc Wittmann’s study on time perception and there was another study by Wackermann et al.4 that you also cited. In this study they also found under-reproduction of time intervals in a very low dose of psilocybin compared to a placebo condition. How does that fit in with your results showing an over-reproduction with a low-dosed psychedelic?
D: So there is a bit of an inconsistency across the studies. I don’t have any concerns about it being an artifact or anything like that. In terms of why there’s a discrepancy: There might be differences between psilocybin and LSD of course. I think a lot of people just put them in the same camp all the time I think that’s something we want to be careful of. Another argument is of course the level of the dose and how comparable these doses are across the two different drugs. The third would be the possibility that there might be different phases with LSD but not with psilocybin. Lastly, I believe their test was conducted 60 to 90 minutes after dose, whereas our testing took place almost three hours after dosing.
L: Another thing that you mentioned in your paper is that this over-reproduction was the most pronounced at a 10 microgram dose. Could you say why you think this dosage would produce the biggest effect?
D: I wouldn’t want to say much about that to be honest. Again, this gets back to this issue that we basically have 12 participants in each condition which is actually pretty good for a psychedelic study but it’s not super sensitive. I wouldn’t overinterpret the fact that the effects are most pronounced in the 10-microgram condition.
One possibility is that because we don’t have baseline effects that we just randomly ended up with a few people in that group that have a baseline tendency for over reproduction and that they just started a little bit higher and then the LSD effects are uniform across the different doses. Because if you look at that figure what we tend to find is that the 20 microgram tended to almost always be higher than the 5 microgram, hinting at some dose effects there. But they might have been disrupted a bit by potential baseline differences.
If you follow the Bayesian model outlined above, focusing on the reproduction times might not be the most valuable way to look at the data. Rather, according to such an account, with greater prior de-weighting, you would expect that the slope of the reproduction times would become steeper (again, reflecting over-reproduction of the longer intervals and under-reproduction of the shorter intervals). Interestingly, we analyzed the slopes of the reproduction times and found that the slope was indeed steepest in the highest dose. Again, we have to be careful given the sample sizes, but this suggests that this interpretation might be more parsimonious.
L: How has conducting this experiment influenced your opinion on microdosing as a practice that supposedly induces all kinds of psychological benefits?
D: I don’t think this study has really informed my opinion on that per se. I think it does provide a good starting point for indicating that there do seem to be some effects on a fundamental feature of consciousness which is time perception. Nevertheless, we have to be careful because time perception is intrinsically linked with attention and working memory and other types of core cognitive functions and it is possible that these effects are totally attributable to changes in attention or working memory. It’s theoretically possible that we are basically modulating attention or working memory and that’s having subsequent kind of carryover effects on time perception.
Now in terms of microdosing more broadly: Probably due to my background in philosophy, I’m by nature a very skeptical person about everything I hear about in science, and I am consistently bombarded with very strong claims and it makes me very nervous. Personally, I wouldn’t just start microdosing in the hopes of enhancing my creativity or cognition or something like that without any kind of evidence base to back that up.
I doubt that there’s going to be like any negative or harmful effects of microdosing. It’s probably going to be, for the most part, harmless. But I think that people just generally should be more skeptical and not jump on some kind of random bandwagon or craze when there’s little empirical base for it. As a scientist I try to base my decisions on the empirical evidence in front of me, and what I can say is I think microdosing is sufficiently interesting from a therapeutic and cognitive standpoint to be conducting more multi-faceted research on.
I’m certainly excited to see more research and I hope that I’ll be able to be involved in some of it, but it always depends on what kind of opportunities arise. I’m hoping that we’ll get a chance to do further research on either microdosing, suprathreshold or even psychedelic doses of these drugs.
L: If you could do whatever you like, what would be your next scientific project?
D: The ideal study I would like to do, if practical limitations were not in place, would again involve a temporary reproduction task. Have the participants complete a task at baseline and then have them complete the task approximately every, say, 45 minutes and go up to in the range of maybe about at least three or four hours and to see the effects there. But I would also do it at multiple microdoses as well as psychedelic doses, so that way we can then dissociate the dosage effects.
Also, I would do a more systematic investigation regarding self-reports of altered states of consciousness. Attention is one thing; we also don’t have any information on emotion. Emotion is known to impact your perception of time, so basically when someone is elated, they may experience time as passing more rapidly and they might underestimate time, whereas if somebody is very depressed then time tends to kind of drag on. I would probably ask some questions about mind wandering and attentional lapses, as well. If we did that we could compare psychedelic versus microdoses and we’d also be able to explore these different phases of the drug and potentially be able to say something more intelligent and more informative regarding if there is robust evidence for these different phases or not.
Also, the self-report measures would be able to tell us in a more systematic way to what extent these effects might be attributable to some type of alteration of consciousness. I feel pretty confident that they’re not attributable to an altered state, but I wouldn’t rule that out completely because we only got to measure a few different dimensions of conscious experience. The effects seem to be independent of the ones we measured but of course we didn’t measure everything; so, there’s a number of things that are unexplored.
L: One final question: We have a lot of students reading the blog, can you give any advice to students looking to work on altered states of consciousness?
D: Working in these fields, I think that you’re at a disadvantage in terms of getting a job and staying in academia, so I think that you have to overcompensate perhaps by publishing more and maybe getting a bit luckier. Nevertheless, I think it’s all about the supervisor and the environment, so anyone that wants to work in these fields should identify a passionate supervisor. Someone who works in the field and can provide appropriate mentorship.
I think there’s also something to be said for doing some mainstream research alongside this type of work to have a kind of a proper grounding in in other research areas. My PhD was on cognitive neuroscience in hypnosis but in the context of that I did a lot of work on executive functioning and cognitive control and a lot of the work I do on time perception is concerned with more conventional aspects of time perception. I think it can be a bit dangerous if you’re working solely on fringe topics because of how you might be perceived by your colleagues. However, beyond all else I tell all my students that it’s critical to identify something you’re passionate about and then pursue that!
“Trasumanar significar per verba non si porìa; però l’essemplo basti a cui esperïenza grazia serba.”
Paradiso I, 70-72
Recently C.J. Büche wrote an in-depth analysis of the role of particular representations of psychedelics in popular media in the “psychedelic renaissance”1. In addition to his work, different ways of describing psychedelics can also be examined in scientific discourse. Paying attention to language choices may offer significant insight into the cultural and personal assumptions of the authors. With due exceptions: in some cases, researchers may have been constrained by funding agencies and ethical committees to describe psychedelics in negative terms, regardless of their own convictions, as a precondition to carry out and publish their studies.
Much like in general media, a variety of contrasting descriptions of psychedelics can be found in scientific media. At least three kinds of language can be identified: in the first, psychedelics are described as with no medical utility and high potential for abuse (“Schedule 1” drugs in all respects)2. In the second , they are considered potentially key to a better understanding of brain function3 and breakthrough treatments4 for otherwise untreatable psychiatric conditions. In the third kind of language, psychedelics are described only or mainly as “psychosis-inducing drugs”5, and considered medically useful in the study of psychotic disorders such as schizophrenia. This subdivision is of course a simplification to some degree: the same authors may use different language in different papers, and “mixed” accounts are also possible.
Schedule 1 Drugs
The first kind of language, summarized by the statement that psychedelics are drugs with a high potential for abuse and no medical utility, has little to no scientific basis6. This stigmatized view of psychedelics can be traced back to a political heritage of the 1970 Controlled Substances Act and the subsequent War on Drugs, and is rapidly disappearing from scientific publications in light of more recent and more rigorous evidence. Nonetheless, it is important to note that:
1) Contemporary clinical trials have been carried out with small sample sizes, highly restrictive screening processes, under constant professional medical supervision, and not always with the possibility of a fully double-blind placebo condition7. All these factors may have contributed to their success. This is not to diminish the impressive results of these rigorous and difficult studies (particularly in treatment-resistant populations); but rather to suggest avoiding hasty conclusions, such as that psychedelics may be risk-free panaceas for any and all psychiatric disorders.
2) While there is evidence that at the population level, the risks of psychedelics have been overstated8, there is no conclusive evidence for the safety of psychedelics at the individual level, and particularly little understanding of persisting effects such as HPPD9. Non-professional “therapeutic” practices involving the use of psychedelics outside clinical settings therefore present a significant amount of risk. This risk is potentially higher than with recreational use, not only because of the high variance in subjective and environmental factors already intrinsic in psychedelic experiences, but particularly because these practices target populations with potentially unaddressed neurobiological issues and high psychological sensitivity.
Tools and Medicines
The second kind of language, which describes psychedelics as useful medicines and important tools for scientific research, (re-)emerged recently with the contemporary and less politically-constrained wave of psychedelic research led by groups at Imperial College London and Johns Hopkins University, among others. The term “psychedelic renaissance” commonly refers to these lines of research, whose merits are many, undeniable, and documented extensively elsewhere10. In this context, it is worthwhile only to remark that some of these studies may also be criticized for using culturally specific terms (e.g. “mystical experiences”, “ego-dissolution”) under the implicit assumption that they reflect somewhat universal or biologically-grounded phenomena, which need not be the case.
For example, non-western cultures using psychedelics may lack the concept of a contemplative “mystical experience”, or the dualistic views of subject/object and internal/external implied by “ego-dissolution”. Therefore, they might experience and interpret the same neurological phenomena according to an entirely different ontology. Influential cognitive theories, such as predictive coding, indeed suggest that cultural and personal expectations (as well as language itself11) should powerfully shape the content and interpretation of psychedelic experiences, in agreement with a long history of observations12.
Models of Schizophrenia-Like Psychosis
The third kind of language is particularly interesting, because it has been and still is quite widespread, despite raising a host of scientific and philosophical questions of its own. Does it make sense to characterize psychedelics only or mainly as “psychosis-inducing drugs”? Is their psychiatric utility only or mainly to be found as models of “schizophrenia-like psychosis”5?
The canonical definition of psychosis is based on hallucinations, aberrant salience, and delusional beliefs, and appears water-tight in identifying pathological cases. However, it is only so because it relies on a specific, shared set of beliefs and assumptions. Language characterizing psychedelics only or mainly as “psychosis-inducing drugs” cannot be fully justified empirically, but instead has to rely on a very specific a priori judgement about the content of psychedelic experiences, as well as unstated assumptions about what constitutes real, how much of it is socially constructed, and importantly in this context, how much of it is accessible through language.
These questions have been the subject of intense philosophical debate for millennia, but are glanced over in some scientific papers using this kind of language. “Reality” is implicitly assumed to be deterministic, mechanistic, and fully encompassed by analytic language and mathematical laws: a worldview still prevalent in life sciences today, inherited from 19th-century physical sciences. However, even physical sciences have long since moved away from this view: Gödel’s incompleteness theorem and the quantum mechanical uncertainty principle, like modern Pillars of Hercules, pose fundamental limits to the systematically knowable reality. Furthermore, the social sciences inform us that much of what we commonly refer to as “real”, or at least acceptable, is determined by societal consensus, not by scientific examination. The humanities posit that language itself, let alone reality, has countless possible interpretations (with the escape of pragmatism: not all interpretations are equally useful).
The definition of psychosis is therefore at least as much culturally and socially determined as it is scientific. Psychedelic experiences, too, are heavily influenced by culture, both in their content and its interpretation. This suggests that particularly in scientific papers regarding psychedelics, all assumptions (e.g. what constitutes “real”, how much of it can be conveyed through language) and constructs (e.g. “psychosis”, “mystical experience”) should not be taken for granted as if they were empirically determined scientific facts, but rather carefully examined to avoid potential confounds.
Is the psychiatric utility of psychedelics only or mainly to be found in modeling “schizophrenia-like psychosis”? At first glance, psychedelic experiences can indeed share common features of schizophrenic psychoses: hallucinations, mania, paranoia. However, research shows that there is no straightforward link between any substance model and schizophrenia13. From a metacognitive viewpoint, after taking psychedelics, most people maintain a sense of the induced experience being somehow different from the ordinary reality of everyday life (note that both may be experienced as “real”, but real in different ways)14. Some schizophrenic patients do exhibit such a “double bookkeeping” pattern, or the ability to distinguish between the ordinary and hallucinatory realities they experience. But this is not true in all cases: in “single-bookkeeping” schizophrenic psychoses, hallucinations and ordinary reality are not distinguishable, and both are automatically taken at face value. In such cases, other substance classes, for example anticholinergic hallucinogens15, would provide a more accurate model. Furthermore, auditory verbal hallucinations, an important hallmark of schizophrenic psychoses16, are not a prominent feature of psychedelic experiences. Once again, a different class of substances (amphetamines) and modality of use (chronic rather than acute) may provide a more suitable model17.
A fortiori, the evidence showing long-term, population-level positive effects of psychedelics on suicidality and mental distress18, as well as the recent clinical trials on depression in terminally ill cancer patients19, clearly show that the psychiatric utility of psychedelics goes far beyond modeling psychosis6. Even if the premise is accepted that psychedelics are only or mainly “psychosis-inducing drugs”, one would have to concoct a convincing explanation for why inducing a “schizophrenia-like psychosis” turns out to be a positive choice for mental health, both at the statistical level in the general population and in medically controlled clinical trials. The available scientific evidence therefore suggests that there is more to psychosis (and even more so to complex psychotic disorders such as schizophrenia) than psychedelics can teach us about it; and vice versa, there is far more to psychedelics than what they can teach us about psychoses and psychotic disorders.
The conclusion seems warranted that language characterizing psychedelics only or mainly as drugs inducing “schizophrenia-like psychosis”, or suggesting any straightforward relation between the two, is at best a limited account, at worst misleading, and based upon unstated and questionable assumptions. For completeness, it is worth remarking that a similar line of criticism could be raised against language characterizing psychedelics only or mainly as “mystical-experience-inducing drugs” or “ego-dissolving drugs”; but this has not been the case in any serious scientific publication to date, hence why the criticism here was directed specifically towards the language of “psychosis-inducing drugs”. The same goes for any other attempt to oversimplify these complex phenomena and reduce them to a single aspect without taking potential cultural and linguistic confounds into account.
Language and Mechanisms: the Ineffable Medicine
For sake of brevity, let’s not discuss the languages of “unifying” theories of psychedelic effects20, which ultimately require a unified theory of conscious experience, an incredibly interesting but extremely difficult task for all the obvious reasons. There is no consensus in the scientific community when it comes to the specific mechanisms that should mediate the potential benefits of psychedelics for psychiatric conditions. Some researchers propose that they are due to reduced inflammation21, others to increased neuroplasticity22, others again (among which the key groups of the psychedelic renaissance) suggest that reaching an ineffable “mystical experience”19 or “ego-dissolving”23 psychological state is actually the crucial factor in the therapeutic process. Back to language again: “The Tao that can be spoken of is not the eternal Tao”. This age-old remark becomes relevant again in the context of psychedelic research. What is the most appropriate language to scientifically study experiences for which perhaps the most common subjective report is that the experience itself lies “beyond” or “outside” of language? Is there anything at all we can say about such ineffable concepts and experiences24?
The emerging picture is fascinatingly complex and far from settled. In the future, language choices will play a crucial role25, as they can build both bridges and walls between (apparently) contrasting theories. Psychedelics seem to resist all attempts at simplistic, systematic, complete characterization: even the most widely accepted neurophysiological mechanism of action (agonism at the 5HT-2A receptor26) does not directly explain why substances with entirely different receptor affinity profiles can have highly overlapping effects with those of psychedelics, for example Salvinorin A27, a kappa-opioid receptor agonist and the active compound in the plant Salvia Divinorum; or ketamine, an NMDA-receptor antagonist with hallucinogenic properties at specific doses28, capable also of increasing neuroplasticity22 and showing great promise in the treatment of depression29. Furthermore, the downstream effects of functional selectivity at the 5HT-2A receptor are still being worked out30, and recent analyses31 show that affinities for muscarinic and opioid receptors may also be relevant for predicting the reported subjective effects. These difficulties might discourage the scientific study of psychedelics, but seen in a different light, they greatly increase the potential contributions of these substances to science and medicine.
In conclusion, these reflections suggest a few general points that, if implicitly understood and explicitly implemented, might be useful to productively move forward in the field of psychedelic research:
Psychedelic research is already stretching the boundaries of scientific language and methods. One might speculate that a paradigm shift in the way we view the relationship between brain processes and subjective experiences will be necessary in order to obtain a fully satisfactory, naturalistic account of these remarkable phenomena.
Or perhaps even that won’t do.
This article was first published on the APRA blog.
1. Büche CJ. The De-Politicisation of Psychedelics [Internet] [Master’s Thesis]. [London]: University College London; 2018 [cited 2019 Jan 30]. Available from: https://medium.com/@celestinjohannesbche/the-de-politicisation-of-psychedelics-bf89d280c9ef?fbclid=IwAR0UmOuaWSD-JkOcxKw0DM83kAxZh1n_8h98VGT82qsODMWIw9oinyA2l7I
2. Hu Q-D, Xu L-L, Gong Y, Wu G-H, Wang Y-W, Wu S-J, et al. Lysergic acid diethylamide causes photoreceptor cell damage through inducing inflammatory response and oxidative stress. Cutan Ocul Toxicol. 2018 Sep;37(3):233–9.
3. Kyzar EJ, Nichols CD, Gainetdinov RR, Nichols DE, Kalueff AV. Psychedelic Drugs in Biomedicine. Trends Pharmacol Sci. 2017 Nov;38(11):992–1005.
4. Schenberg EE. Psychedelic-Assisted Psychotherapy: A Paradigm Shift in Psychiatric Research and Development. Front Pharmacol [Internet]. 2018 Jul 5 [cited 2019 Jan 30];9. Available from: https://www.frontiersin.org/article/10.3389/fphar.2018.00733/full
5. Vollenweider FX, Vollenweider-Scherpenhuyzen MF, Bäbler A, Vogel H, Hell D. Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action. Neuroreport. 1998 Dec 1;9(17):3897–902.
6. Rucker JJH. Psychedelic drugs should be legally reclassified so that researchers can investigate their therapeutic potential. BMJ. 2015 May 26;350(may26 20):h2902–h2902.
7. Carhart-Harris RL, Goodwin GM. The Therapeutic Potential of Psychedelic Drugs: Past, Present, and Future. Neuropsychopharmacology. 2017 Oct;42(11):2105–13.
8. Krebs TS, Johansen P-Ø. Psychedelics and Mental Health: A Population Study. Lu L, editor. PLoS ONE. 2013 Aug 19;8(8):e63972.
9. Litjens RPW, Brunt TM, Alderliefste G-J, Westerink RHS. Hallucinogen persisting perception disorder and the serotonergic system: A comprehensive review including new MDMA-related clinical cases. Eur Neuropsychopharmacol. 2014 Aug;24(8):1309–23.
10. Nichols D, Johnson M, Nichols C. Psychedelics as Medicines: An Emerging New Paradigm. Clin Pharmacol Ther. 2017 Feb;101(2):209–19.
11. Lupyan G, Clark A. Words and the World: Predictive Coding and the Language-Perception-Cognition Interface. Curr Dir Psychol Sci. 2015 Aug;24(4):279–84.
12. Al-Issa I. Social and cultural aspects of hallucinations. Psychol Bull. 1977;84(3):570–87.
13. Steeds H, Carhart-Harris RL, Stone JM. Drug models of schizophrenia. Ther Adv Psychopharmacol. 2015 Feb;5(1):43–58.
14. Fortier M. Sense of reality, metacognition, and culture in schizophrenic and drug-induced hallucinations [Internet]. Vol. 1. Oxford University Press; 2018 [cited 2019 Jan 30]. Available from:http://www.oxfordscholarship.com/view/10.1093/oso/9780198789710.001.0001/oso-9780198789710-chapter-16
15. Lakstygal AM, Kolesnikova TO, Khatsko SL, Zabegalov KN, Volgin AD, Demin KA, et al. DARK Classics in Chemical Neuroscience: Atropine, Scopolamine, and Other Anticholinergic Deliriant Hallucinogens. ACS Chem Neurosci [Internet]. 2019 Jan 10 [cited 2019 Jan 30]; Available from: http://pubs.acs.org/doi/10.1021/acschemneuro.8b00615
16. Hugdahl K. Auditory hallucinations in schizophrenia: the role of cognitive, brain structural and genetic disturbances in the left temporal lobe. Front Hum Neurosci [Internet]. 2008 [cited 2019 Jan 30];1. Available from: http://journal.frontiersin.org/article/10.3389/neuro.09.006.2007/abstract
17. Bramness JG, Gundersen ØH, Guterstam J, Rognli EB, Konstenius M, Løberg E-M, et al. Amphetamine-induced psychosis – a separate diagnostic entity or primary psychosis triggered in the vulnerable? BMC Psychiatry [Internet]. 2012 Dec [cited 2019 Jan 30];12(1). Available from: http://bmcpsychiatry.biomedcentral.com/articles/10.1186/1471-244X-12-221
18. Hendricks PS, Thorne CB, Clark CB, Coombs DW, Johnson MW. Classic psychedelic use is associated with reduced psychological distress and suicidality in the United States adult population. J Psychopharmacol (Oxf). 2015 Mar;29(3):280–8.
19. Griffiths RR, Johnson MW, Carducci MA, Umbricht A, Richards WA, Richards BD, et al. Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial. J Psychopharmacol (Oxf). 2016 Dec;30(12):1181–97.
20. Swanson LR. Unifying Theories of Psychedelic Drug Effects. Front Pharmacol [Internet]. 2018 Mar 2 [cited 2019 Jan 30];9. Available from: http://journal.frontiersin.org/article/10.3389/fphar.2018.00172/full
21. Flanagan TW, Nichols CD. Psychedelics as anti-inflammatory agents. Int Rev Psychiatry. 2018 Jul 4;30(4):363–75.
22. Ly C, Greb AC, Cameron LP, Wong JM, Barragan EV, Wilson PC, et al. Psychedelics Promote Structural and Functional Neural Plasticity. Cell Rep. 2018 Jun;23(11):3170–82.
23. Roseman L, Nutt DJ, Carhart-Harris RL. Quality of Acute Psychedelic Experience Predicts Therapeutic Efficacy of Psilocybin for Treatment-Resistant Depression. Front Pharmacol [Internet]. 2018 Jan 17 [cited2019 Jan 30];8. Available from: http://journal.frontiersin.org/article/10.3389/fphar.2017.00974/full
24. Priest G. The logic of Buddhist philosophy goes beyond simple truth [Internet]. Aeon. 2014 [cited 2019 Jan 30]. Available from: https://aeon.co/essays/the-logic-of-buddhist-philosophy-goes-beyond-simple-truth
25. Slaney KL, Maraun MD. Analogy and Metaphor Running Amok: An Examination of the Use of Explanatory Devices in Neuroscience. J Theor Philos Psychol. 2005;25(2):153–72.
26. Halberstadt AL. Recent advances in the neuropsychopharmacology of serotonergic hallucinogens. Behav Brain Res. 2015 Jan;277:99–120.
27. Roth BL, Baner K, Westkaemper R, Siebert D, Rice KC, Steinberg S, et al. Salvinorin A: A potent naturally occurring nonnitrogenous opioid selective agonist. Proc Natl Acad Sci. 2002 Sep 3;99(18):11934–9.
28. Powers III AR, Gancsos MG, Finn ES, Morgan PT, Corlett PR. Ketamine-Induced Hallucinations. Psychopathology. 2015 Sep 12;48(6):376–85.
29. Newport DJ, Carpenter LL, McDonald WM, Potash JB, Tohen M, Nemeroff CB, et al. Ketamine and Other NMDA Antagonists: Early Clinical Trials and Possible Mechanisms in Depression. Am J Psychiatry. 2015 Oct;172(10):950–66.
30. Perez-Aguilar JM, Shan J, LeVine MV, Khelashvili G, Weinstein H. A Functional Selectivity Mechanism at the Serotonin-2A GPCR Involves Ligand-Dependent Conformations of Intracellular Loop 2. J Am Chem Soc. 2014 Nov 12;136(45):16044–54.
31. Zamberlan F, Sanz C, Martínez Vivot R, Pallavicini C, Erowid F, Erowid E, et al. The Varieties of the Psychedelic Experience: A Preliminary Study of the Association Between the Reported Subjective Effects and the Binding Affinity Profiles of Substituted Phenethylamines and Tryptamines. Front Integr Neurosci [Internet]. 2018 Nov 8 [cited 2019 Jan 30];12. Available from: https://www.frontiersin.org/article/10.3389/fnint.2018.00054/full
Predictive coding “is as important to neuroscience as evolution is to biology.”
—Lars Muckli, neurophysiologist, University of Glasgow1
A few days ago, I was sitting at my desk working when I felt something cold touch my bare foot. Since I knew a cat was in the room, and the sensation felt just like a cat’s cold nose, I was one-hundred percent sure, when I glanced down at my foot, that I would see the cat there. But when I looked down, I saw that one of the straps of my messenger bag had come undone and was dangling from an adjacent chair, the metal attachment piece level with my foot. I looked across the room: the cat was sound asleep in its bed.
This is an example of how the brain continually generates models1 of the world around it in order to predict the most plausible explanation for what’s happening in each moment. Cognitive psychologists call this process predictive coding, and they now believe it can account for most of what’s going on in the brain. The problem is, the brain sometimes gets it wrong, and this discrepancy can result in everything from mild cognitive dissonance to learning disorders to anxiety and depression.
Let’s take a look at how predictive coding works and why it’s being considered a “grand unified theory of cognition” in many scientific circles, as well as a promising framework for understanding the mental health benefits of psychedelics.
What Is Predictive Coding?
The long-standing classical view of perception maintains that we experience the world in three steps: 1) receive input from our environment; 2) process input in higher levels of brain; 3) respond to input accordingly. But an alternative theory has been gaining ground as a more accurate explanation for what’s going on: not only does information flow from our senses to our higher faculties, but those higher faculties often “predict” the input from our environment, thereby influencing our perception of it2 before we actually sense it. This is called predictive processing, or predictive coding.
“You experience, in some sense, the world that you expect to experience,” says Andy Clark, a cognitive scientist at the University of Edinburgh in Scotland. “All experience is controlled hallucination.”1
The purpose of predictive coding is to help us organize our experience of the world as efficiently as possible. Otherwise, life would be a bit of a struggle. Imagine if every time you looked at a tree, it was as if you were seeing a tree for the first time, or couldn’t simply categorize bark as bark but were constantly in awe of the different texture and color of each tree trunk or branch you saw while walking through a forest. Our predictive brains help us see trees as trees, hardly without even looking at them, so that we can quickly put that “old” or “irrelevant” information into a box and move on. A good comparison would be the way a computer stores video files, which contain enough redundancy from one frame to the next that it’s more efficient to encode the differences between adjacent frames and then work backward to interpret the entire video than to encode every pixel in every image when compressing the data.
Although we may think we have really “looked at” the trees around us, we don’t truly see them unless we make a point of paying more attention. For all intents and purposes, the trees are just perceptive models generated by the brain until we really look at them. Even when we do take a closer look, what we perceive is heavily influenced by what we expect to see. And sometimes what we expect to see may not represent the full picture.
“If the brain is an inference machine, an organ of statistics, then when it goes wrong, it’ll make the same sorts of mistakes a statistician will make,” says Karl Friston, a neuroscientist at University College London. “That is, it will make the wrong inferences by placing too much or too little emphasis on either predictions or prediction errors.”1
That’s why the best evidence for the predictive coding model can be found in cases where the brain predicts too much or too little. Individuals with autism would presumably have a weak predictive filter, meaning they have a harder time categorizing trees as trees and moving on. Instead, they get caught up in the texture of the bark. This would explain their extreme sensitivity to input from the environment: Everything is surprising and new, which can be overwhelming. On the other end of the spectrum is schizophrenia, which reflects an overly strong predictive filter3: If your brain is too certain about what it’s looking at, it will override new information with its own beliefs and create false perceptions (read: hallucinations). Most of us are somewhere in the middle of the spectrum. That is, unless we do (or take) something to change our brain chemistry.
Enter psychedelics – Why Does Predictive Coding Matter?
Research on psychedelic substances offers some of the best confirmation for the predictive coding theory. Instead of increasing brain activity, substances like psilocybin and LSD remove the predictive filter4 which normally influences our perception of daily life. When we’re no longer predicting or “explaining away” those trees, we’re suddenly able to consider alternative perceptions of them. The leafy branches undulate like octopus arms and the bark looks delightfully crunchy not because the drugs have added anything to our perception of reality but because they have removed a very narrow filter that’s normally there. They literally allow us to see other equally real possibilities.
A research team at the University of Minnesota explains: “Psychedelic drugs perturb universal brain processes that normally serve to constrain neural systems central to perception, emotion, cognition, and sense of self.”4
If you think about it this way, the cognitive dissonance I experienced when I realized the cat was across the room could be considered a kind of trip: my brain generated a “prediction error” the same way it would if I’d been hallucinating on magic mushrooms. It’s equally “trippy” when you have been wearing eye glasses for a while and reach up to adjust their position on your nose only to remember you put contacts in several hours ago, or when you’ve tricked your brain to falsely associate visual and sensory cues as in this rubber hand illusion. In fact, studies have shown that people with Charles Bonnet Syndrome (partial retinal blindness) will start to see shapes and faces where there are none because that predictive mechanism wants to fill in the missing details to make sense of the world. The number of hallucinations even increased or decreased according to how much light was in the room during the study.
There’s little difference between these perceptual phenomena and what’s happening under the influence of psychedelics; it’s all about the contrast between what you expect to see and what you actually see.
So why does any of this matter? What does it change? The short answer is, a lot. The above examples are all very neutral, but when deeper aspects of life like your sense of self or your perception of other people become involved, that contrast or “prediction error” can be a highly emotional experience. For example, the concept of seeing other possibilities is extremely useful when it comes to psychotherapy. Neuroscientists now have reason to believe5 that psychedelics work to treat conditions like depression and anxiety by influencing the mechanics of predictive coding in this way. One theory is that they stop us from habitually and rigidly predicting future scenarios (anxiety) and future selves (depression), instead opening our minds up to alternative ways of perceiving the situation.
“Very typical of the many existing symptoms in depressed patients is the inescapable loop of thoughts revolving around the patient’s inferiority, a mental state commonly known as rumination,” writes clinical neuroscientist Christoph Benner in the MIND blog. Benner says this happens in the Default Mode Network (DMN), which is active when we think about ourselves. “A non-dynamic behavior means that the DMN is very rigid functionally within its defining brain structures. That is, because of the DMN’s rigidity in depressed patients, there is a tendency towards a negative thinking pattern about oneself.”
Neuroscientists think this loop is interrupted6 when you introduce a drug like psilocybin or ketamine to the system, which results in higher connectivity of the DMN with other brain areas, meaning the patient finally has the cognitive flexibility to think of other, non-depressing things.
“To my mind,” says Dr. Philip Corlett, Associate Professor of Psychiatry at Yale University, “these drugs expand the possibility space—the number of models that could be learned over and about—and so they bump people out of their depression/anxiety rut.”6
Predictive coding also has important implications for learning and memory. First, it sheds light on an interesting Catch-22: In order to learn new things, the predictive mechanism must be reduced to some extent, but in order to retain new information and use it in the future, we need to generate a predictive model of that information. Somewhere in between, in a delicate balance of these two processes, lies optimal learning and memory.
Research on predictive coding and working memory capacity7 provides some good insight into how this might operate. As the current theory has it, when working memory capacity starts to break down, it’s not because our brain gets “too full”; it’s because we can no longer efficiently predict and categorize incoming information. The burning question, then, is this: If we can train our brains to better categorize information before we receive it, can we enhance working memory capacity?
In the same breath, can we learn more by reducing our urge to predict and categorize the information around us so quickly? Does “openness” or “open-mindedness” lead to greater learning because it prevents us from putting information in a box and moving on, and lets us linger and see things from different perspectives, leading to deeper and more complex observation?
Changing the Language We Use
The underlying theme here is balancing predictions with possibilities. Can we teach ourselves how to do this in the context of various mental processes and states of mind such as learning, memory, anxiety, and depression?
One big first step in this experiment is to change the language we use: To what extent do we “predict” ourselves and the people around us, and how does that affect our happiness and success in the world? What can we do to increase our perception of “possibility,” to introduce awe and surprise into our lives, whether it’s shaking up our routine or meditating on a more desirable state of mind?
By revealing our own limits to us, predictive coding also allows us to transcend them.
2. Pink-Hashkes, S. (2017). Perception is in the Details: A Predictive Coding Account of the Psychedelic Phenomenon
3. Friston, K., et al (2014). The functional anatomy of schizophrenia: A dynamic causal modeling study of predictive coding, Schizophrenia Research, 158(1-3). doi: 10.1016/j.schres.2014.06.011
4. Swanson, L. (2018). Unifying Theories of Psychedelic Drug Effects, Frontiers in Pharmacology, 9(172). doi: 10.3389/fphar.2018.00172
5. Corlett, P. (2017). I Predict, Therefore I Am: Perturbed Predictive Coding Under Ketamine and Schizophrenia, Biological Psychiatry, 81(6), 465-466. doi: 10.1016/j.biopsych.2016.12.007
6. Corlett, P., (2016). The role of psychedelics in palliative care reconsidered: A case for psilocybin, Journal of Psychopharmacology, 30(12), 1212-1214. doi: 10.1177/0269881116675781
“Everything that helps us progress could be a good thing to do, even if it scares us at first – as does everything, that’s big and new.”
– Engelbert Winkler1
There are many ways to alter your consciousness and encounter a psychedelic experience. Methods apart from psychedelic substances include deep meditation, breathing techniques, music, ecstatic dancing, or flickering light – to mention just a few.
We at MIND provide experimental workshops and self-experiences in which altered states can be explored, legally and safely. In this first explorative offer, we induce an altered state with flickering light. The light device we use is the Lucia N°03, which is a combination of stroboscope and halogen light bulbs that can induce a hypnagogic experience, an altered state of consciousness between wakefulness and sleep. The effect of Lucia N°03 can also be described as Flicker Induced Hallucination (FIH).
In 1819, the physiologist J. E. Purkinje2 was one of the first who scientifically described this effect, which he induced by facing the sunlight with closed eyes and making shadows with his hands. In 1963, the neurophysiologist W.G. Walter3 also reported on this phenomenon after stumbling upon it during a diagnostic session for epilepsy. His patients described patterns and colors appearing in front of their closed eyes3. Based on his findings, the poet and painter Brian Gysin invented the Dream Machine in the 60s4.
In 2009, the psychologist and psychotherapist Engelbert Winkler and the psychologist and neurologist Dirk Proeckl invented the “Lucia light”, based on findings from research into near-death experiences and hypnotherapy and their use of stroboscopes and halogenic light in their practices5. Since then it has been used by artists, in wellness facilitation, and therapists, to mention just a few.
In March 2018, MIND began offering light experiences to those interested. Lying on a massage chair, with their favorite music playing in the background, participants are safely guided through the experience by one of our ‘Light Attendants’. As one lies comfortably with the eyes closed, the light turns on and the psychedelic experience begins. Each session starts with a two- and a five-minute-long demo session of varying intensity, after which the light traveler chooses one of the many possibly Lucia programs. Every session with the Lucia light is highly individual and depends not only on the person, but also on their whole mindset: the mood, the attentiveness and the playfulness, curiosity, and openness to the experience. What the experiences with the Lucia light usually have in common is an intensity that is hard to put into words, although some have tried.
Here are some user remarks (translated by the author from German into English):
“I saw my favorite color, super intense, and it came in a pattern which reminded me of my mother’s sewing machine. I feel like I want to be in a sewing factory and tailor clothes with all those beautiful patterns.”1
“I felt like I was dreaming or sleeping, I’m not sure I was awake the whole time. But I can remember beautiful patterns moving towards me, three-dimensional, and it felt like I could see 180°. I feel very calm now.”1
“What is it good for? Well, to uphold the beauty in life—what else?”1
Since MIND’s clinical partner organization OVID started to provide psychedelic-augmented psychotherapy in February 2021 MIND does not offer such experimental sessions with the lamp anymore. Stroboscopic light sessions have become part of the prepration for ketamine-assisted psychotherapy. There it plays the role of a low-threshold learning tool: with the lamp, people are invited to explore their mind and their body in a relaxed and curious manner, build awareness for their inner processes, self-confidence and train their ability to let go and accept processes with as little judgement as possible.
1. Winkler EJ. Streben nach Sein – das Sonnenspiel: Die Entwicklung des heliotropen Atmens für Therapie, Selbsterfahrung und Psychonautik. Santler H, editor. Textmaker; 2016.
2. Purkinje J. Beiträge zur Kenntnis des Sehens in subjectiver Hinsicht [Internet]. Prague: Vetterl; 1819. 176 p. Available from: http://echo.mpiwg-berlin.mpg.de/MPIWG:DFKXMEUG
3. Walter WG. Das Lebende Gehin – Entwicklung und Funktion. München/Zürich: Knaur; 1963. 246 p.
4. Eulen BC, Tavy D, Jacobs BC. From Stroboscope to Dream Machine: A History of Flicker-Induced Hallucinations. European Neurology. 2009;62(5):316–20.
5. Light Attendance GmbH. Statement zur Wirksamkeit von Lucia N°03. [Internet]. 2015. Available from: http://www.gesund-im-licht.at/downloads/2015%20Statement%20zur%20Wirksamkeit%20Lucia%20N03%2020150823%20engl%20dt%20www.pdf