6: Consciousness

The mind-brain problem: What is mind? #

  • The nature of the mind-body or mind-brain connection was a philosophical question of importance in the early days of cognitive science
    • What is mind? Is it something that is physical? Is a body necessary to have a mind?
    • We don’t talk too much about philosophy since it’s inherently not empirical / verifiable
      • It’s all that was possible 50 years ago
      • Now we have neuroscience!

Different viewpoints #

Monism #

There is only one kind of substance in the universe

  • Idealism: Everything – including the material world – is actually mind
  • Materialism: Everything that exists – including mind – is physical
    • In some fundamental sense, the mind just is the brain, so that everything that happens in the mind is happening in the brain
    • Aristotle: The brain is like a lump of clay; the different thoughts the mind can take on when it undergoes different patterns of activity are like the shapes the clay can assume
    • Most cognitive scientists hold this view

Dualism #

Belief in the existence of both mental (e.g., “soul”) and physical substances

  • The mind and brain are two separate and distinct things
    • Religious viewpoint
  • Few cognitive scientists are dualists

Functionalism #

  • What makes something a thought, desire, pain (or any other type of mental state) is solely its function, or the role it plays, in the cognitive system of which it is a part
  • More specifically, the identity of a mental state is said to be determined by its causal relations to sensory stimulations, other mental states, and behavior
  • Ex: pain as a state that tends to be caused by bodily injury; to produce the belief that something is wrong with the body and desire to be out of that state; to produce anxiety
    • Suppose that, in humans, there is some distinctive kind of neural activity (e.g., C-fiber stimulation) that meets these conditions, then humans can be in pain simply by undergoing C-fiber stimulation
    • However, theory permits creatures with very different physical constitutions to have mental states as well, e.g., silicon-based states of hypothetical Martians
    • It is also logically possible for non-physical substrates to give rise to mental states, e.g., some sort of energy field
      • Functionalism is actually officially neutral between materialism and dualism, but it tends to be associated today with materialism, and specifically, the view that each type of mental state is identical with a particular type of neural state
        • This type of “species-chauvinism” is a modern phenomenon due in large to an increased emphasis on neuroscience in the last 25 years

Intelligence And The Physical Symbol System (PSS) Hypothesis #

  • One of central ideas of philosophy of artificial intelligence
  • Proposed in 1975 by computer scientists Herbert Simon and Allen Newell
  • Holds that all intelligent behavior essentially involves transforming physical symbols according to rules
    • GEB Ch 1-3 ++

  • A physical symbol system is basically an abstract characterization of a digital computer

Statement of hypothesis: A physical symbol system has the necessary and sufficient means for general intelligent action

  • Implications:
    1. Anything capable of intelligent action is a physical symbol system
      • Since humans are capable of intelligent action, the human mind must be a physical symbol system
    2. Since a physical symbol system is sufficient for intelligence, machines can be constructed that are intelligent

John Searle’s Chinese Room #

  • Imagine a person who does not understand Chinese in a closed room
  • Person receives pieces of paper through one window and passes out pieces of paper through another window
  • The pieces of paper have symbols in Chinese written on them
  • In the room is a huge instruction manual that tells the person in the room which pieces of paper to pass out depending on which pieces of paper he receives
  • To all intents and purposes, the person in the room is responding in Chinese
  • But he does not in fact understand Chinese

So what does it really mean to “understand” something, to be fully “conscious”?

  • Tries to show that the physical symbol system hypothesis is completely mistaken
  • Describes a situation in which symbols are manipulated to produce exactly the right outputs, but where there seems to be no genuine understanding and no genuine intelligence
  • Searle also thinks that the Chinese room argument reveals a fundamental problem with the so-called Turing Test…

Turing test #

  • Proposed by Alan Turing in 1950 as a criterion for whether a machine is displaying real intelligence
  • If an observer is communicating with a machine and cannot tell the difference between it and a human being, then that would show that the computer was genuinely intelligent
  • Participants: Human interrogator (judge), one human responder, and one “machine” responder
  • Neutral communication: No visibility or other clues (e.g., all three are responding through computer terminals, so no handwriting or “voice” clues)
  • Interrogation: The interrogator asks the other agents (human and machine) a series of questions

  • Resolution: After a fixed time interval the interrogator tries to decide which is the “human” participant

Rebuttal to the Chinese room argument #

  • Rebuttal says that…
    • The Chinese room does not understand Chinese, but only because it is disembodied
    • The ability to understand Chinese involves, at a minimum, being able to carry out instructions given in Chinese, to coordinate with other Chinese speakers, and to carry on a conversation
    • In order to build a machine that could do all this, we would need to embed the Chinese room in a robot, providing it with some analog of sensory organs, vocal apparatus, and limbs
    • Then the system could be said to understand Chinese and behave intelligently
  • Searle’s response to robot reply
    • The basic problem still remains: simply manipulating symbols cannot create meaning
    • There must be more to genuine thinking than simply manipulating symbols according to rules
    • Aside: Does Google Translate understand Language?
      • Not really. We just feed it enough data such that it can make fairly-accurate predictions. It doesn’t understand language in that it can’t distinguish the meaning. So can some system, given enough resources (power, time, information, etc)?
      • Then again, humans wouldn’t understand an Alien language… we still have un-deciphered languages written by humans!

What is consciousness? #

  • Consciousness is generally defined in psychology as “awareness of our environment and our perceptions, images, and feelings”
  • However, exactly what consciousness is is perhaps the most hotly debated issue in the modern philosophy of mind
    • What is consciousness? Does it exist in all creatures? Is there some part of the brain or some particular pattern of neural activity that gives rise to consciousness?
  • Some philosophers, like John Searle, have argued that consciousness is an emergent property of a physical brain
    • That is, it may not be fully explained by an understanding of its component parts
  • More recently, neurologists have also jumped into this debate…

Neural correlates of consciousness #

  • Neuroscientists generally hold that consciousness results from the coordinated activity of a population of neurons
  • But which neurons? What exactly are the neural correlates of consciousness (NCC), i.e., the minimal set of neural events sufficient for a specific conscious experience? (Christof Koch)
  • Currently, there are two main theories:
    • Global Neuronal Workspace Theory (Baars, Dehaene & Changeux)
    • Integrated Information Theory (Guilio Tononi)

Global Neuronal Workspace Theory #

Global workspace theory: Explains how information is made accessible for high-level cognition, action, and speech

  • When we are conscious of something, many different parts of our brain have access to that information
    • E.x. the language/motor/planning module will all have access to this information
  • When we act unconsciously, that information is localized to the specific sensory motor system involved
    • Ex: When you type fast, you do so with little conscious awareness, so that, if asked how you do it, you would not know
      • Information is localized in brain circuits linking your eyes to rapid finger movements
      • The modules don’t know the meaning of the information given to them (they’re unconscious)
      • Low level, implies that this is subconscious
  • Global workspace theory maintains that consciousness forms when specialized programs or modules access a shared repository of information or “blackboard”
    • Data written onto this blackboard becomes available to a host of subsidiary processes, such as working memory, language, the planning module, etc.

Consciousness emerges when incoming sensory information, inscribed onto the blackboard, is broadcast globally to multiple cognitive systems

Global Neuronal Workspace (GNW) Theory #

  • Evolved from global workspace theory
  • The network of neurons that broadcasts messages widely is hypothesized to be located in the frontal and parietal lobes
  • Theory proposes a distributed network of high-level processors, most likely in the prefrontal, parieto-temporal, and cingulate cortices
  • Because the blackboard has limited space, we can only be aware of a little information at any given instant
    • Attention makes low-level modular information available for conscious control in the global workspace
  • Once that information is broadcast on the network and is globally available, it becomes conscious

Cortical regions important in consciousness #

Frontal and parietal #

  • Evidence that network of neurons that broadcast messages widely is located in the frontal and parietal lobes:
  • Various types of nonconscious processing are associated with deficits in these areas, including….


1. Hypnosis #

  • Hypnosis is associated with
    1. Decreased activity in the dorsal anterior cingulate
      • When hypnotized, you are in a state so absorbed in listening that one is not thinking about anything else
      • No selective attention
    2. Reduced connections between the dorsolateral prefrontal cortex (motor actions) and the default mode network (awareness of one’s actions), which includes the medial prefrontal and the posterior cingulate cortex – why you do not recall being hypnotized

2. Repression and Dissociation #

  • Repressed memories
    • Recovered memories of child abuse
  • Dissociative identity disorder (multiple personality)
    • Condition in which two or more identities or personalities alternate in control of a person’s behavior
      • One personality can be diabetic, near-sighted, or allergic to a substance and the other not
      • The two personalities can have different brain waves, vital signs and hormonal levels
    • Some personalities are aware of the other personalities
  • Research indicates that in repression/dissociation, the prefrontal cortex (executive control) disengages processing in the hippocampus (memory)
    • Participants asked to memorize word pairs, e.g., ordeal-roach or steam-train
      • Respond condition: Participants were shown cue word and asked to recall the matched word
      • Suppress condition: Participants were shown cue word and asked to actively suppress the matched word
        • Word suppression was associated with activation of prefrontal cortex to disengage processing in hippocampus
        • Suppressing matched word reduced later recall of word

      Takeaway: Brain is actually more active when avoiding recalling a memory than during recall itself - Perhaps why mindfulness is impactful

3. Lucid dreaming #

  • Whereas dreams are unconscious, lucid dreams are conscious
  • Lucid dreaming: Neuroimaging data is scant but preliminary results suggest that prefrontal and parietal regions are also involved in lucid dreaming
    • Currently, there is only one fMRI study contrasting lucid and non-lucid REM sleep and it is a case study (Dresler, Wehrle, Spoormaker et al., 2012)
      • Few people who can lucid dream at will => few potential subjects
    • Interestingly though, the results of this study converge with MRI studies that have evaluated individual differences in lucid dreaming frequency (Baird, Castelnovo, Gosseries et al., 2018)
  • Compared to non-lucid REM sleep, lucid REM sleep is associated with increased activity in
    • Prefrontal cortex (metacognition and self-reflection)
    • Parietal cortex and the precuneus (self-referential processing, episodic memory, and experience of agency)
    • Occipital and inferior temporal regions (visual processing)
      • Lucid dreams are oftentimes associated with increased visual vividness and clarity of the dream scene

4. Unilateral spatial neglect #

  • Visual neglect syndrome or unilateral spatial neglect:
    • Tendency to ignore – or to be unaware of – information on one half of visual field, usually the left side
    • Typically occurs after damage (e.g., stroke) to right hemisphere, particularly damage to the parietal and frontal lobes

    Patients are asked to draw from memory or to copy an illustration (Driver & Vuilleumier, 2001)

Posterior hot zone #

  • However, other research suggests that it is primarily regions in the “posterior hot zone” – not the prefrontal – that generate the sights, sounds, and other sensations of life as we experience it

Electrical stimulation of cerebral cortex #

  • Prior to removing a brain tumor or locus of a patient’s epileptic seizures, neurosurgeons map functions of nearby cortical tissue by directly stimulating it with electrodes
    • Stimulating the posterior hot zone triggers a variety of distinct sensations and feelings
    • Stimulating the frontal cortex by and large elicits no direct conscious experience
  • Similar effects have been found after removal of cortical tissue
    • Removal of large sections of frontal cortex (e.g., prefrontal lobotomy) does not significantly affect conscious experience, though patient may develop problems with emotional control, motor deficits, or uncontrollable repetition of specific actions or words
    • However, removal of even small regions of the posterior cortex can lead to loss of an entire class of conscious content – patients may be unable to recognize faces or to see motion, color, or space

Brain-injured patients #

  • One possible reason for the discrepancy in research findings is that the part of the cerebral cortex that is primarily associated with consciousness depends on the type of consciousness in question
  • In particular, some philosophers have distinguished between two types of consciousness:
    • Access consciousness (or A-consciousness):
      • Pertains to accessibility of information, i.e., conscious vs. nonconscious information processing
      • Prefrontal and parietal cortical areas may play important roles in this
      • Related to the “easy problem” of consciousness: explaining in computational or neural terms how an organism accesses and deploys information
    • Phenomenal consciousness (or P-consciousness):
      • Pertains to how and why we experience the world as we do
      • Posterior hot zone may play critical role in this
      • This is what David Chalmers has called the “hard problem” of consciousness
        • Why and how is it that sentient organisms have qualia or phenomenal experiences?
        • Why and how is it that some internal states are felt states (e.g., heat or pain), rather than unfelt states (e.g., seeing a thermostat or a toaster)?

  • The Global Neuronal Workspace Theory of consciousness lends insight to access consciousness
  • However, it does not address the problem of phenomenal consciousness
  • Integrated Information Theory, which will be turning to shortly, does address the latter

Cerebellum #

  • One thing though that most researchers agree on is that the seat of consciousness is not located in the cerebellum, though this part of the brain contains
    • Four times as many neurons as the cortex
    • Half the total number of neurons in the whole brain People who lack a cerebellum (either from birth or as a result of brain injury) are still capable of conscious perception, leading a “normal” life without any loss of awareness

      Suggests that sheer number of neurons is not a decisive factor in the creation of conscious experience

  • But why?
    • One reason might be that the cerebellum’s processing mostly happens locally with minimal interactions between neurons
    • The cerebellum is almost exclusively a feed-forward circuit with no complex feedback loops that reverberate with electrical activity passing back and forth
    • It’s functionally divided into hundreds of independent computational modules with distinct, non-overlapping inputs and output, controlling movements of different motor or cognitive systems
    • This idea that exchange and integration of neural signals is the basis of phenomenal consciousness is one of the main ideas of integrated information theory

Integrated Information Theory #

  • In the early 2000s, Guilio Tononi pioneered a technique called zap and zip to probe whether someone is conscious or not
    • Scalp of patient was “zapped” with an intense pulse of magnetic energy using TMS (transuranium magnetic stimulation)
    • This induced a brief electric current in the neurons underneath, which would reverberate across the cortex, exciting and inhibiting other neurons
    • A network of EEG sensors recorded those electrical signals, and as they unfolded over time, yielded a movie
    • The data from the movie was compressed using an algorithm commonly used to “zip” computer files
    • Zipping yielded an estimate of the complexity of the brain’s response

    Loss and recovery of integration and information in thalamocortical networks:

    A: Wakefulness
    B: Anesthesia

    C: Vegetative state: UWS (unresponsive wakefulness syndrome), MCS (minimally conscious state), LIS (locked-in syndrome)

  • Research findings from zap and zip:
    • Volunteers who were awake had a “perturbational complexity index” significantly highly than when deeply asleep or anesthetized
    • Method was subsequently able to correctly determine whether patients were conscious or in a vegetative state
    • Measures of the brain’s responses to the TMS also seem to predict the consciousness of patients in a non-communicative and vegetative state– a finding with potentially profound clinical applications
      • This suggests that the more information that is shared and processed between many different components of the brain in response to a single experience, the higher the level of consciousness
    • This is the main idea of integrated information theory (IIT): Consciousness arises from neural integration and complexity
      • Similar to what GNWT says – different parts of brain that can access information are higher level
  • If information integration theory is right, it would have implications far beyond neuroscience and medicine
    • For instance, proof of consciousness in a creature, such as a lobster, could transform the fight for animal rights
    • It would also answer some long-standing questions about AI
      • Tononi argues that the basic architecture of the computers we have today – made from networks of transistors – precludes the necessary level of information integration that is necessary for consciousness (given our current medium we cannot represent consciousness)
        • Even if they can be programmed to behave like a human, they would never have our rich internal life
        • He emphasizes this is not just a question of computational power or the kind of software that is used

          “The physical architecture is always more or less the same, and that is always not at all conducive to consciousness”

Xenobots #

  • Potential for consciousness in xenobots (“living robots”)?
    • Created by scientists from skin cells and heart cells in the form of stem cells harvested from frog embryos
    • Xenobots are able to move in a coherent fashion to explore their watery environment and can survive for days or weeks, powered by embryonic energy stores
    • Made of organic material (thus, biodegradable) so it shouldn’t cause long-term issues
  • Functions
    • Groups of xenobots can move around in circles, pushing pellets into a central location
    • Others were built with a hole through the center and were able to use that as a pouch to successfully carry an object
    • When xenobot was cut in half, it stitched itself back up and kept going
  • Potential applications
    • Serving as new material for technologies that is fully biodegradable
    • Intelligent drug delivery: carrying medicine to a specific place in body
    • Traveling in arteries to scrape out plaque
    • Searching out and break down harmful compounds or radioactive wastes
    • Gathering microplastics in the oceans

Criticism of IIT #

  • Tononi’s methods (zap n zip) so far only offer a very crude “proxy” of the brain’s information integration
    • To really prove his theory’s worth, more sophisticated tools will be required that can precisely measure processing in any kind of brain
  • One problem is that, using previous techniques, the time taken to measure information integration across a network increases “super exponentially” with the number of nodes under consideration

Controversies in CogSci: #

What are some potential strengths and weaknesses of Tononi’s Integrated Information Theory?

Evidence for unconscious processes #

  • Some prominent psychologists today maintain that 100 years of research has provided no clear evidence for the existence of the “unconscious,” but that claim seems to be exaggerated
  • By one estimate, our five senses take in 11,000,000 bits of information per second, of which we consciously process about 40
  • Some specific evidence for the existence of the unconscious…

Consciousness and thought suppression #

  • White bear/red Volkswagon study
    • Goup 1: Participants were told to try not to think about white bears
    • Goup 2: Participants were told to try not to think about white bears but if they did, to replace the thought with the image of a red Volkswagon
  • Which group was more successful?
    • Group 2:

    It’s very difficult (if not impossible!) to suppress a maladaptive thought; it’s much easier to replace the thought with a more desirable one (Wegner, Schneider, Carter et al., 1987)

Unconscious behaviors #

  • Split brain:
    • A condition in which the two hemispheres of the brain are isolated by severing the connecting fibers (mainly those of the corpus callosum) between them
    • After operation, patients often notice that left hand seems to have a “mind of its own”

      Suggests that consciousness involves operations of verbal mechanism located in left cerebral hemisphere

  • Freudian slips
    • Lood gegs
    • Bine foddy

Unconscious perception #

  • Subliminal perception and priming
  • Rope tying study
    • Participants are asked to tie together two strings that are hanging from the ceiling
    • The strings are separated so that they can’t reach one of them while holding the other
    • A table and pliers are made available
    • At some point, the researcher walks into the room and accidentally sets one of the strings swinging
    • Invariably, within a few minutes, the participant would figure out the solution to the problem…

      When interviewed afterwards though, they said that the idea “just came to them” (Maier, 1931)

  • Surgery patients in double-blind study wore earphones during their operations, listening to either
    1. Soothing background music and
    2. Positive suggestions about the safety and success of the procedure
    • Results: Compared to controls, experimental group
      • Woke up feeling significantly less pain (25% on average)
      • Required less pain medication post-surgery (70 required no opiates at all, compared with 39 in the control group) (Nowak, Zech, Asmussen, et al., 2020 )

Unconscious communication #

  • Study on 23-year-old woman who showed no outward signs of conscious awareness after being in a car accident (Owen, Coleman, Boly et al., 2006; wn, 2014)
    • When researchers asked her to imagine playing tennis vs. walking around her home, fMRI scans revealed activity in regions similar to healthy person’s brain
  • Follow-up analysis of 42 behaviorally unresponsive patients revealed 13 more who also showed meaningful though diminished brain responses to questions (Stender, Gosseries, Bruno et al., 2014)
    • Researchers wonder if such fMRI scans might enable a “conversation” with some unresponsive patients, by instructing them, for example, to answer yes to a question by imagining playing tennis

Repressed memories #

  • Recovered memories of child abuse
  • Dissociative identity disorder (multiple personality)
  • Anosognosia: “unawareness of illness”
    • Stroke patients with this disorder may deny that his arm is paralyzed

Unconscious conditioning in advertising #

  • Men shown picture of car with sexy woman standing in front judged car to be more appealing, better designed, more expensive, faster, and less safe than control group of men
    • However, 22 out of 23 participants denied their rating had been influenced by the presence of the model

      “I never let myself be blinded by advertising; the car itself is what counts"

Unconscious processing and sexual attraction #

  • We are often influenced by factors of which we are entirely unaware
  • Suspension bridge study:
    • Males were interviewed by attractive female supposedly as part of research project, either
      • Just after crossing a narrow, wobbly footbridge 230 feet above rapids OR
      • 10 minutes after crossing the bridge
    • They were given the researcher’s telephone number in case they had questions later
      • Those in first condition were much more likely to call to ask for a date afterwards
      • Participants had no idea their attraction was influenced by the situation (Meston & Frohlich, 2003)
      • Powerful idea (beyond sexual attraction)
        • You don’t know how green the grass is on the other side (how much better things really are) if you never make the effort (choose free will)
        • If you are already where the grass is greener, you don’t recognize or fully appreciate the processes that lead you here

Unconscious learning (Extra) #

  • Unconscious learning: behavioral responses can be reinforced through associations without person’s awareness
  • Double agent experiment
    • Graduate student interviewer was told to nod his head whenever participant engaged in a particular behavior (e.g., chin rubbing) order to reinforce this behavior
    • “Interviewer” was actually the real participant in the experiment; the participant was a confederate
    • “Participant” was instructed to rub his chin whenever the interviewer said “yeah”
      • Frequency of interviewer’s saying “yeah” increased substantially
    • When interviewer was eventually told what had happened, his reaction was one of “stunned incredulity” (Rosenfeld & Baer, 1969)
  • Thumb twitch study
    • Participants were told that they were participating in a study on effects of stress on body tension and that effects of stress would be manipulated by randomly alternating periods of soothing music and static
    • In fact, noise was not presented randomly: it was terminated whenever participants contracted a very small muscle in their left thumb that could only be detected by an electrode
    • Participants in uninformed group were told nothing about how static could be turned off
    • Participants in partly informed group were told that static could be turned off by specific response and to try to discover that response
    • Results:
      • Dramatic increase in contractions of this muscle in all participants
      • However, interview afterwards revealed that all the participants in uninformed group still believed they had no control over the noise
      • Only one participant in the partly informed group believed that he had discovered the effective response, which involved “subtle rowing movements with both hands, infinitesimal wriggles of both ankles, a slight displacement of the jaw to the left, breathing out, and then waiting” (Hefferline, Keenan, Harford et al., 1959)

Controversies in Cognitive Science #

  • What are some of the implications of the computational model of mind generally? And more specifically, with regard to consciousness?
  • What are some limitations of the computational model of mind?

Altered States of Consciousness #

Hypnosis #

  • Hypnosis: social interaction in which one person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur

Hypnotic susceptibility #

  • Hypnotic susceptibility: Correlated with measures of imagery vividness and absorption – people who are hypnotically susceptible tend to have rich fantasy lives and easily become absorbed in the imaginary events of a novel or movie

Uses of hypnosis #

Hypnotic recovery of memories #

Use of hypnosis in treatment of physical and psychological disorders #

  • But can also cause people to construct false memories and to increase their confidence in these false memories
    • Hypnotized witnesses may end up testifying confidently to events they never experienced
    • Latter is particularly problematic because highly hypnotizable subjects are especially vulnerable to false memory suggestions
  • Hypnotherapy: Clinical applications of hypnosis
    • Hypnosis quite successful in treating physical disorder (e.g., warts, headaches, asthma)
    • Not so successful in treating psychological disorders (e.g., smoking, overeating, alcoholism)
    • Recovery rate for latter increases though when combined with other therapies like systematic desensitization

Hidden observer #

  • Research by Hilgard suggests that a dissociated part of the hypnotized person (the hidden observer) is aware of what is happening even when person is ostensibly unaware
    • Ice water study: person kept smiling while hidden observer wrote, “This is agony, let me out!”
    • Lemon study: person seemed to be enjoying “orange,” while hidden observer yelled out “You’ve just squirted acid in my mouth!”

Use of hypnosis in pain control #

  • Use of hypnosis in childbirth
    • Standard hypnotherapy
    • Hypnobirthing: combination of self-hypnosis and childbirth education
  • A number of studies have indicated that hypnobirthing is associated with shorter hospital stays, shorter length of labor, reduction in self-reported pain, reduced epidural and analgesic use
  • However, other studies have found inconclusive results, so overall more research is needed
  • Mechanism:
    • There are sensory and emotional components of pain perception
      • Sensory component is mediated by somatosensory cortex
      • Cognitive/emotional component is mediated by the anterior cingulate cortex and the prefrontal cortex
        • fMRI studies using hypnotic suggestion found that a decrease in the unpleasantness of pain reduced the activation of the anterior cingulate cortex without affecting the activity of the somatosensory cortex

Hallucinogens #

  • History
    • Used in Aztec, Mayan, Incan, West African, South Asian, and Egyptian societies since ancient times
      • To promote physical and mental healing
      • To induce spiritual experiences and access “altered states of consciousness”
    • 1960s emergence of counterculture movement led to widespread usage of hallucinogens in the US
    • Social/cultural differences in use of hallucinogens
      • Largely part of underground lifestyle in the West
      • Openly used for spiritual purposes in other parts of the world


  • LSD: Lysergic Acid Diethylamide
  • Drug action:
    • Stimulates serotonergic and dopaminergic receptors – not fully understood
  • Positive effects:
    • Causes perceptual distortions and hallucinations: “altered states of consciousness”
      • Emotions can vary from euphoria to detachment or panic
    • Sense of self may dissolve, as does boundary between oneself and external world
    • Research has indicated that LSD may be effective for treating anxiety due to terminal illness, alcoholism, and cluster headaches
  • Adverse effects:
    • No documented fatalities from pharmacological action of LSD, but behavioral fatalities and suicides can occur
    • May trigger panic attacks and extreme anxiety (“bad trips”); flashbacks
    • May trigger psychotic break, especially in those with family history of schizophrenia
  • Maps page

MDMA, Ecstasy #

  • Drug action:
    • Causes release of serotonin, norepinephrine (adrenaline), and dopamine, and blocks their reabsorption
  • Positive effects:
    • Emotional elevation, disinhibition, feelings of connectedness with everyone
    • Research has indicated that MDMA may be effective for treating PTSD
  • Adverse effects:
    • Dehydration, overheating, and increase in blood pressure can cause death, especially when combined with dancing at raves
    • “Ecstasy” pills may be cut with dangerous chemicals
    • Potential damage to serotonin-producing neurons, leading to increased risk of depression and sleep problems
      • Less serotonin the next morning, can also be long-term if used too much
    • Memory impairments
  • Maps page

Psilocybin #

  • Drug action:
    • Stimulates serotonin receptors
  • Positive effects:
    • Causes euphoria, perceptual distortions, hallucinations
    • May induce spiritual experiences
      • Marsh Chapel Experiment on Harvard Divinity School students in 1962
      • Participants reported profound religious experiences
      • In 25-year follow-up, all of the participants described experience as having elements of “a genuine mystical nature and characterized it as one of the high points of their spiritual life”
      • Single administration induced significant increase in personality dimension of openness to experience that persisted for over a year
    • May be effective in treating depression and OCD
  • Adverse effects:
    • May cause nausea, panic attacks, confusion, and psychotic episodes, leading to accidents and suicide attempts

Psychedelic therapy #

  • Abram Hoffer study in the 1960’s
    • Gave alcoholics a small dose of mescaline, then deliberately induced peak experiences by means of music, poetry, painting – whatever used to produce peak experiences before the person became alcoholic
      • 50% were supposedly permanently cured
  • Moratorium on research in this area from early 1970s to early 2000s due to war on drugs
  • However, resurgence of interest and research in this area in recent years, in particular with regard to use of hallucinogens – especially MDMA and LSD – to treat substance abuse, PTSD, obsessive-compulsive disorder, depression, cluster headaches, and emotional suffering associated with terminal illness
  • UCB launched the campus’s first center for psychedelic science and public education in 2020
    • Will conduct research using psychedelics to investigate
      • Cognition, perception, emotion and their biological bases in the human brain
        • Initial studies will focus on psilocybin
      • Integration of psychedelics with psychotherapy to treat psychological disorders and brain mechanisms involved
      • Ability of these compounds to improve cognitive flexibility, alter visual perception, engender feelings of awe and change patterns of brain activity
    • Center also plans to collaborate with the Graduate Theological Union and eventually train guides or facilitators, in the cultural, contemplative and spiritual care dimensions of psychedelics

Mysticism or psychosis (Extra!) #

“From the first, the experience seemed to me to be holy. What I saw was the Power of Love – the name came to me at once – the Power that I knew somehow to have made all the universes, past, present and to come; to be utterly infinite, an infinity of infinities, to have conquered the Power of Hate, its opposite, and thus created the sun, the moon, the planets, the earth, light, life, joy and peace, never ending….In that peace I felt utterly and completely forgiven, relieved from all burden of sin. The whole infinity seemed to open up before me, and during the weeks and months that followed I passed through experiences which are virtually indescribable. The complete transformation of “reality” transported me as it were into the Kingdom of Heaven. I feel so close to God, so inspired by His Spirit, that in a sense I am God. I see the future, plan the Universe, save mankind; I am utterly and completely immortal; I am even male and female. The whole Universe, animate and inanimate, past, present and future is within me; all things are possible.”

Answer: Psychotic episode of John Custance

All at once, without warning of any kind, I found myself wrapped in a flame-colored cloud. For an instant I thought of fire, an immense conflagration somewhere close by in that great city; the next, I knew that the fire was within myself. Directly afterward there came upon me a sense of exultation, of immense joyousness accompanied or immediately followed by an intellectual illumination impossible to describe. Among other things, I did not merely come to believe, but I saw that the universe is not composed of dead matter, but is, on the contrary, a living Presence; I became conscious in myself of eternal life, but a consciousness that I possessed eternal life then; I saw that all men are immortal; that the cosmic order is such that without any peradventure all things work together for the good of each and all; that the foundation principle of the world, of all the worlds, is what we call love, and the happiness of each and all is in the long run absolutely certain.”

Answer: Mystical experience of R.M. Bucke, Canadian psychiatrist

“When I walk the fields, I am oppressed, now and then, by an innate feeling that everything I see has a meaning, if only I could understand it. And this feeling of being surrounded with truth, which I cannot grasp, amounts to indescribable awe sometimes. Have you not felt that your real soul was imperceptible to your mental vision, excepting a few hollow moments?”

Answer: Mystical experience of Charles Kingsley, a Christian mystic

“I am simple; I need not think. Feeling is all; feeling is love. God is love. Love is the expression of God. Feeling is only fire. Fired by God. The dancer becomes the divining motion. Dance is the divine in the world. The Dionysian religion. Love is God. I am love; I am God.”

Answer: Psychotic experience of Nijinsky, Russian ballet dancer

  • Distinctions:
    • The mystic, unlike the person with psychosis, develops a strong sense of self
    • The mystic tends to reduce self-importance; psychosis tends to involve inflated self-importance
    • The mystic tends to have ever increasing serenity, which leads him or her to be more involved in life and more loving towards all beings; those with psychosis have difficulty relating with anybody and clearly withdraw from the world
    • The mystical experience, though ineffable, is usually coherent and what is described is clear; those with psychosis tend to be thought-disordered so their descriptions are not very lucid
    • The mystical experience is usually brief, though it leaves so vivid an imprint that it can be remembered clearly 25 years later; in psychosis, the person may get stuck in the experience and be unable to come out of it
    • In mysticism, there is a gradual reduction of attachment to the world; in psychosis, there is a fusion and a continuous shifting of the world
    • The mystic tends to take responsibility, not only for themselves, but for all aspects of life around them; those with psychosis project out of themselves those things that seem especially negative

Near-Death Experience #

  • Near Death Experience: an altered state of consciousness reported after a close brush with death
    • Reported by about 10 to 15 percent of those revived from cardiac arrest
    • Many describe visions of tunnels, bright lights or beings of light, a replay of old memories, and out-of-body sensations
  • Physiological explanation

    They suggest that damage to the bilateral occipital cortex may lead to visual features of NDEs such as seeing a tunnel or lights, and “damage to unilateral or bilateral temporal lobe structures such as the hippocampus and amygdala” may lead to emotional experiences, memory flashbacks or a life review. They concluded that future neuroscientific studies are likely to reveal the neuroanatomical basis of the NDE which will lead to the demystification of the subject without needing paranormal explanations

  • Typical report:

    “I was left with an awareness that something more was going on in life than just the physical part of it… There is more than just consuming life, more than just what we can buy. There comes a point when you have to give in to it… The typical near-death survivor emerges from his experience with a heightened appreciation for life, determined to live life to the fullest. He has a purpose in living even though he cannot articulate just what the purpose is.”

Controversies in CogSci: Implications and limitations of the computational model of mind #

  • Ultimately, the experiences that Altered States of Consciousness involve cannot really be captured by language…

Cognitive Neuroscience of Consciousness #

  • As discussed earlier, various types of nonconscious processing are associated with suppression of or reduced activity in parts of the frontal and parietal cortices
    • Hypnosis is associated with reduced activity in the dorsal anterior cingulate and reduced connections between various regions of the frontal cortex that are part of the default mode network (self-awareness) and the motor cortex
    • Non-lucid dreaming, in comparison with lucid dreaming, is associated with reduced activity in areas of the prefrontal and temporoparietal lobes involved in self-referential processes
    • Study by Michael C. Anderson found that in repression, the prefrontal cortex (executive control) disengages processing in the hippocampus (memory)
  • Other important brain structures:
    • Anterior cingulate cortex (ACC)
      • Forms “collar” around front part of corpus callosum
      • Functions:
        • Integrates cognitive and affective information
        • Awareness and processing of conflicting information
        • Selective attention

    • Insular cortex
      • Lies deep within the lateral sulcus
      • Functions:
        • Self-awareness
        • Consciousness
        • Emotional regulation


  • In addition, study on repression found that autonomic arousal during free association task
    • Predicted subsequent memory failure
    • Was accompanied by increased activation of conflict-related brain regions (e.g., anterior cingulate cortex) and deactivation of memory-related regions (e.g., hippocampus) (Schmeing, Kehyayan, Kessler, et al., 2013)
  • When patients with dissociative identity disorder read stories that pertained to their trauma (Simone Reinders), the alters that were unaware of the trauma, relative to alters that were aware of the trauma, showed
    • Increased activity in cingulate gyrus
    • Reduced amygdala and insula activity
    • Reduced cardiovascular response