Consciousness & Intelligence PDF

Consciousness & Intelligence and Unconscious Processes I. The mind-brain problem: What is mind? A. Intelligence and the physical symbol system (PSS) hypothesis B. Searle’s Chinese Room thought experiment − Turing test II. What is consciousness? A. Neural correlates of...

Consciousness & Intelligence and Unconscious Processes I. The mind-brain problem: What is mind? A. Intelligence and the physical symbol system (PSS) hypothesis B. Searle’s Chinese Room thought experiment − Turing test II. What is consciousness? A. Neural correlates of consciousness B. Global Neuronal Workspace Theory of consciousness C. Cortical regions important in consciousness 1. Frontal and parietal a. Hypnosis b. Repression and dissociation c. Lucid dreaming d. Unilateral spatial neglect 2. Posterior hot zone a. Electrical stimulation of cerebral cortex b. Brain-injured patients 3. Cerebellum  D. Two types of consciousness − The hard problem of consciousness E. Integrated Information Theory ☛ Controversies in CogSci: Strengths and weaknesses of IIT as a theory of consciousness III. Evidence for unconscious processes A. Consciousness and thought suppression B. Unconscious behaviors C. Unconscious perception D. Repressed memories E. Unconscious conditioning in advertising F. Unconscious learning  The Mind-Body 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? 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 o In some fundamental sense, the mind just is the brain, so that everything that happens in the mind is happening in the brain o 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 o 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 − Few cognitive scientists are dualists Functionalism, on the other hand, holds that we need to emphasize function, to understand how things produce their effects 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 Ø 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 Functionalism (understanding how things produce their effects) results in a high-level understanding that can be implemented in multiple different ways That is, those functions no longer have to be tied to a specific type of structure or material, e.g., neurons or the brain Ø For example, one can imagine a silicon-based Martian having the same headache pain as an earthling, but because of the Martian's different neurophysiology, different physical properties are instantiated 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 (Stanford Encyclopedia of Philosophy)  Which Philosophical View Best Explains the Data? All of the different philosophical views discussed above, e.g., idealism, dualism, the various forms of materialism, can potentially explain anything, including altered states of consciousness This also means that there isn’t a way to definitively “disprove” another point of view Ø For example: Materialist: You can have all kinds of experiences, but they’re still materially implemented. Idealist: Yes, but all of your materially-based data is actually just something that is happening within the mind. Materialist: That perception that it’s all just something happening within the mind is materially covered. It’s epiphenomenal. Idealist: Yes, but all of your observations and reasoning on this subject are still being done by the mind. ➜ Either of these positions can be considered fundamental − Which view people subscribe to really depends on what they are most comfortable with, intuitively – neither can be said to be more logical v “At the Supreme Court level where we work, 90% of any decision is emotional. The rational part of us supplies the reasons for supporting our predilections.” – Justice William Douglas Intelligence & 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 ✧ 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 Rule-governed Thinking = manipulation of symbolic representation structures In humans, symbol systems are The same symbol systems can also be instantiated in the brain instantiated in a computer  John Searle’s Chinese Room Argument ✧ 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 Ø Searle’s Chinese Room thought experiment − 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”? 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  Turing Test (TT) 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 Ø Rebuttal to the Chinese room argument 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 Ø 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  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, neurobiologists 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 of Consciousness 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 When we act unconsciously, that information is localized to the specific sensory motor system involved Ø 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 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 (as described in previous slide) 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 (remember the filter model of attention?) Once that information is broadcast on the network and is globally available, it becomes conscious 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: − Hypnosis − Repression and dissociative identity disorder − Non-lucid (as opposed to lucid) dreaming − Unilateral visual neglect ✧ Hypnosis is associated with Decreased activity in the dorsal anterior cingulate (selective attention) − So absorbed that one is not thinking about anything else 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 (Jiang, White, Greicius et al., 2016) ✧ 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) Ø Participants asked to memorize word pairs, e.g., ordeal-roach or steam- train (Michael C. Anderson) − 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 ★ Brain is actually more active when avoiding recalling a memory than during recall itself ✧ 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) 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) v Lucid dreams are oftentimes associated with increased visual vividness (Baird, Mota-Rolim, Dresler, 2019) and clarity of the dream scene 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) 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  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., a thermostat or a toaster)? ✤ According to Frank Jackson’s Knowledge Argument, a colorblind scientist who knew every (third-person) scientific act about color perception would still lack first-person knowledge of what it is like to see color – and would probably be quite shocked if he saw a red rose for the first time ✧ 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, nonoverlapping 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 (transcranial 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 Ø Data from zap and zip: 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 Ø Research findings from zap and zip: Volunteers who were awake had a “perturbational complexity index” significantly higher 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 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 Ø 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 − 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 v “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 ✧ 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 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 – meaning that, even with the best technology, the computation could last longer than the lifespan of the universe Daniel Toker at UCB has recently proposed a shortcut for the mathematical calculations necessary to test the theory  ☛ Controversies in Cognitive Science v What are some potential strengths and weaknesses of Tononi’s Integrated Information Theory?  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 (Timothy D. Wilson, 2002) Some specific evidence for the existence of the unconscious… Consciousness and thought suppression Ø White bear/red Volkswagon study o Group 1: Participants were told to try not to think about white bears o Group 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 This tendency to only be conscious of and identify with the left-brain self is also evidenced in alien hand syndrome, also known as Dr. Strangelove syndrome Alien hand syndrome: person experiences their limbs acting seemingly on their own and lacking conscious control over the actions Condition most commonly affects the left hand At times, the alien hand may even try to harm the individual There are a variety of possible causes, including stroke, tumor, trauma, or a neurodegenerative disorder The disorder may involve damage to − Corpus callosum − Medial frontal lobe: control of movements − Parietal lobe: sensory feedback regarding movements Freudian slips “Good morning, beheaded – uh, I mean beloved.” Ø 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) Subconscious processing under anesthesia: Surgery patients in double-blind study wore earphones during their operations, listening to Soothing background music and Positive suggestions about the safety and success of the procedure Ø 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 Ø 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; Owen, 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 Ø 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 v“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 Ø Suspension bridge study - Males were interviewed by attractive female supposedly as part of research project, either o Just after crossing a narrow, wobbly footbridge 230 feet above rapids OR o 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) Unconscious learning: behavioral responses can be reinforced through associations without person’s awareness Ø Double agent experiment Graduate student interviewer was told to nod his head whenever participant engaged in a particular behavior (e.g., chin rubbing) in 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) Ø 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”  ☛ Controversies in Cognitive Science v What are some of the implications of the computational model of mind generally? And more specifically, with regard to consciousness? v What are some limitations of the computational model of mind?  Video References Videos excerpted from: Discovering Psychology: The Mind Hidden and Divided https://www.learner.org/series/discovering- psychology/the-mind-hidden-and-divided/ This is the First LIVING Robot and it's Unbelievable https://www.youtube.com/watch?v=js6uTRT8KO4