CogSci_2Consciousness-3.pdf

Consciousness & Intelligence 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. Global neuronal workspace theory of consciousness B. Integrated information th...

Consciousness & Intelligence 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. Global neuronal workspace theory of consciousness B. Integrated information theory C. Neural correlates of consciousness D. Two types of consciousness − The hard problem of consciousness E. IIT and the zip and zap technique 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 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) 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 instantiated in the brain The same symbol systems can also be instantiated in a computer Newell and Simon’s General Problem Solver program (1957): way of solving problems using means-end analysis, is an example of heuristic search (a rule-of-thumb strategy that reduces the number of operations to solve a problem) Evaluate the difference between the current state and the solution state Identify a transformation that reduces the difference between the current state and the solution state May need to divide problem into sub-problems and move backwards Ø Hobbits-and-Orcs Problem: - Imagine that 3 Hobbits and 3 Orcs all arrive at the right side of a riverbank, and they all want to cross to the left side. Fortunately, there is a boat. However, the boat is small, and it can hold only two creatures at one time. Moreover, whenever there are more Orcs than Hobbits on one side of the river, the Orcs will immediately attack the Hobbits and gobble them up. Therefore, you must be absolutely certain that you never leave more Orcs than Hobbits on any riverbank. How would you solve this dilemma? ☞ Sometimes it may be necessary to move backwards – problem-solvers are often unwilling to do this! 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 ✧ Currently, there are two main theories: − Global Neuronal Workspace Theory or GWT (Baars, Dehaene & Changeux) o Consciousness emerges when incoming sensory information, inscribed onto a blackboard, is broadcast globally to multiple cognitive systems 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 − Integrated Information Theory or IIT (Guilio Tononi) o Consciousness arises from neural integration and complexity Ø Zap and zip technique 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) Ø Evidence that network of neurons that broadcast messages widely (GWT) 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 ✧ 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, nearsighted, 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 steamtrain (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 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) ✧ 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 nonlucid 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 Compared to non-lucid REM sleep, lucid REM sleep showed increased activity in Prefrontal cortex (metacognition and selfreflection) 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 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 ✧ 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)? Ø 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 Integrative information theory addresses the question of phenomenal consciousness and is one of the “hottest” topics in the cognitive science of consciousness 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 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 (ITT): 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” 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 Intelligence ✧ Intelligence, as discussed above, relates to consciousness and the ability to understanding meaning, not to IQ ✧ However, students often ask what exactly it is an intelligence test measures, so following are some examples… Until the last century, the understanding of intelligence was strictly related to cognitive functions, such as: Memory Learning Problem-solving ➜ IQ tests dominated the field Sample Questions from WAIS (Wechsler Adult Intelligence Scale): VERBAL General Information What day of the year is Independence Day? Similarities In what way are wool and cotton alike? Arithmetic Reasoning If eggs cost 60 cents a dozen, what does 1 egg cost? Vocabulary Tell me the meaning of corrupt. Comprehension Why do people buy fire insurance? Digit Span Listen carefully and when I am through, say the numbers right after me. 7 3 4 1 8 6 Now I am going to say some more numbers, but I want you to say them backward. 3 8 4 1 6 PERFORMANCE Picture Completion I am going to show you a picture with a part missing. Tell me what is missing. Picture Arrangement The pictures below tell a story. Put them in the right order to tell the story. Block Design Using the four blocks, make one just like this. Object Assembly If these pieces are put together correctly, they will make something. Go ahead and put them together as quickly as you can. Digit-Symbol Substitution Bell curve for IQ tests is roughly centered around 100: Problems with IQ Tests Motivation for development of notion of emotional intelligence: Standard IQ tests are problematic for a number of reasons… Cultural and other biases Underlying assumption of IQ tests that intelligence is innate and fixed undermines motivation Standard IQ test aren’t very effective at predicting success in life Cultural Biases in IQ Tests IQ tests largely measure vocabulary (correlation of 0.8, according to some sources) ➜ Problem: by age 3, children from higher income families have heard 30 million more words than those who are less privileged! Even subsections of IQ tests that supposedly measure reasoning ability may be biased Ø Ex: Question on WISC (Wechsler Intelligence Scale for Children) that asked why someone might want to purchase fire insurance Research has shown that standard IQ tests aren’t very effective at predicting success in life Ø Academically high-aptitude people are NOT more effective in - achieving better marriages - successfully raising their children - achieving better mental and physical well-being So alternative ways of defining and assessing intelligence have been developed, such as Multiple Intelligence Multiple Intelligence In 1983, Howard Gardner published a groundbreaking work “Frames of mind: The theory of multiple intelligences.” These intelligences included: linguistic logical-mathematical spatial musical bodily-kinesthetic interpersonal intrapersonal He later added: existentialist naturalist Gardner’s theory of multiple intelligence was Based on neurological data on brain function Supported by research on savants (people who show superior ability in one intellectual domain, such as music, art, or mental arithmetic but are born with severe intellectual disability) v It’s been said that dance may be one of the only activities that develop all of the different types of intelligences… Dreams and the Unconscious: Why Do We Dream? Freud’s wish-fulfillment theory of dreams: dreams are a safety valve that discharges otherwise unacceptable feelings/desires Modern psychodynamic view Dreams reflect what is going on in our lives, our hidden impulses and desires, and underlying conflicts Dreams give clues to the solution of our underlying conflicts and problems Hobson & McCarley’s activation-synthesis hypothesis Dreams serve no purpose – just side effect of random firing of neurons that serve to develop and preserve neural pathways through stimulation Cognitive development theory of dreams The neural activation associated with dreaming aids cognitive development – Peak of REM sleep occurs in 30-week-old fetus, who spends almost 24 hours a day in this state Memory consolidation view Participants who were trained on visual search task or word learning, then deprived of REM sleep, performed significantly worse than control participants the next morning (Stickgold, 2012) REM sleep increases following stressful experiences or periods of intense learning (graduate student studying for Qualifying Exams) Unconscious problem solving Great discoveries and inventions have often come to people through dreams Man who discovered the structure of the benzene molecule had dream of snake chasing its own tail Dream Analysis Basic technique: 1) Recall dream in as much detail as possible as soon as you awaken To enhance dream recall, try not to move: stay in same position Try to fully recall emotions of the dream 2) Keep a scribble pad by your bed and take notes 3) Interpret dream In general, dream dictionaries are of limited value: we all have our own unique symbols Focus on emotional interpretation – not academic interpretation (What did you feel in dream? Where do you feel like that in your life?) 4) Apply the dream to your everyday life Make a decision or choice, then put it into action Conscious Dreaming: Lucid Dreams Lucid dream: Dream in which one is aware that one is dreaming and is thus able to direct the course of the dream Induction of lucid dreams Practice dream recall – Learn to recognize your most frequent or characteristic dreamsigns (elements of dreams that indicate that you are dreaming) Get up for an hour in the middle of the night Practice reality testing: Ask yourself several times a day whether you are dreaming and remind yourself of dream events that can prompt lucidity (e.g., flying, dreamsigns) Use autosuggestion - Remind yourself throughout the day that all things are of the nature of dreams Strengthen intention and desire: visualize yourself recognizing that you are dreaming and carrying out an intended action Use of other techniques: – Recall your dream when you awaken and replay it while visualizing yourself recognizing that you are dreaming – Test different sleeping positions – Use an electronic dream induction device like the Nova Dreamer Video References Videos excerpted from: Discovering Psychology: The Mind Hidden and Divided https://www.learner.org/series/discoveringpsychology/the-mind-hidden-and-divided/