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
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
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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:
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
Since a physical symbol system is sufficient for intelligence, machines can be constructed that are intelligent
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…
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
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!
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…
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)
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
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
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
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
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
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
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
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”
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
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
Even with the best technology, the computation could last longer than the lifespan of the universe
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…
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)
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
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
Soothing background music and
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 )
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
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 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)
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: 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
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!”
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
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
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
“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: 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
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Ultimately, the experiences that Altered States of Consciousness involve cannot really be captured by language…
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
Extra:
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
Patients are asked to draw from memory or to copy an illustration (Driver & Vuilleumier, 2001)
