COGST 1101

Modularity of Brain Functions

principle of segregation: the idea that the brain and mind are not homogeneous - the brain can be divided into parts (both in terms of anatomy [broadmann map] and function [ventral/dorsal visual pathways) principle of integration: the idea the no part of the brain can function on its own, or is anatomically isolated from the rest of the brain large scale differentiation: processing of the left visual field is differentiated from processing in the right visual field because early sensory areas are contralaterally organized -- this is consistent with the idea that some functions are segregated in the brain evidence for/against: wada test and other demonstrations of localization of function

Behaviorism

psychology as the scientific study of behavior; John B. Watson (1913); everything we need to know about the mind is observable; behavior is determined by prior learning and external events; learning occurs according to set rules

A Challenge from Tolman's Rats (2)

radical behaviorism: behavior is determined by reinforcement learning, what's in mind is irrelevant BUT rats still learn maze without reinforcement, and learn WHERE reward is, not just movements that lead to it, so there must be something important between stimulus and response; because behavior alone can't explain maze learning there must be some kind of mental representation

Behavioral Outcomes Related to Postive and Negative Reinforcing/Punishing Stimuli

reinforcing: add positive = good gain, remove negative = good loss -> behavior becomes more likely; punishing: add positive = bad gain, remove negative = bad loss -> behavior becomes less likely

HM

removal of bilateral medial temporal lobe (MTL) at age 27; normal intellect, personality, conversational skills, nothing obviously wrong, but what about his memory? anterograde amnesia: loss of the ability to create new memories after event that caused amnesia; retrograde amnesia: loss of memory-access to events that occurred before onset of amnesia

Transformational Grammar

rules that allow for the reordering and addition/deletion of components; On a log sat three turtles (deep) -> Three turtles sat on a log (surface); deep structure: abstract structure of a sentence; surface structure: superficial form of a sentence; phrase structure rules: rules that identify the components of a sentence; why is language productivity a challenge to behaviorism? -> behaviorism implies reinforcement; 2 things are critical for language: algorithms (transformational grammar) and representations (innate rules, phrases)

Phantom Limbs

sensation that a missing limb is still present; V.S ramachandran's remapping hypothesis: sensory input from face and arm can extend into the hand region of the sensory strip; cortical plasticity in early sensory areas triggered by changes in body (amputations) and changes in use (practice)

Operant (Instrumental) Conditioning

skinner box; three-term contingency theory: behavior modification occurs as a result of outcomes; discriminative stimulus -> behavior -> outcome, but does outcome influence behavior? examples: pecking light and getting reward, lever to get out of box, cat stops digging when shocked, NOT drool when light turns on

Other Divisions/Interesting Facts About HM

some memories are declarative (explicit knowledge of events and facts) and other memories are nondeclarative (implicit and procedural); knew that he didn't have new memories, perceptual knowledge)

Stages of Processing

stimulus -> person -> response [stimulus -> sensory processing -> perceptual processing -> storage -> response] task analysis (lashley): cognitive tasks can be broken down into parts and sub-parts

Representations

symbolic/propositional: abstract representations (more information can be processed if recoded); analog: more direct association with thing being represented (eg. mental rotation -- rotating in mind is analogous to rotating in life); hierarchical: parts and subparts (eg. alignment and distortion of cognitive maps)

Justification for Using Animal Models

tecnhiques: whole brain imaging, whole slice imagine, single cell imaging, EEG, whole brain imagine, single cell; valence/emotional learning: phobias, anxiety, PTSD, aversions (taste), stop unwanted behaviors, encourage repetition of behaviors, addictions, overeating, education

Attention

the cocktail party effect: one channel, many messages; dichotic listening: people can easily filter irrelevant ear; ignored messages are just "attenuated"; is ignoring successful? not always; unattended stimuli are still processed (sometimes they capture your attention eg. name and they can influence behavior eg. stroop effect/errors in dichotic listening)

Lateral Geniculate Nucleus (LGN)

the midway point for the visual information from the retina to travel to the visual cortex; when there's an edge (contrast of light and dark) the net activation of RG isn't zero and sends useful information about the edge of the object -- this is contrast coding

Identity Theory

the mind is the brain

Receptive Fields

the part of the visual field that is coded by a neuron; an RF gets excited if its on-area gets stimulated, and inhibited if its off-area gets stimulated

Stroop Effect & Interference Insights

the printed word interferes with naming the color; some processes are automatic; 2 "channels" can have different messages; relevant information must be selected; irrelevant information can still influence behavior; idea: automatic response when see word red but not as strong when congruent

Cognition

thought (but not just conscious thought) that includes things that happen in our heads that we are not necessarily aware of or able to describe

Visual Maps

topographically organized; central visual field is over-represented; scotoma: damage to part of the map leads to blindness for that region of space

Visual Processing Streams (Pathways)

ventral stream ("what" pathway) vs. dorsal stream ("where" pathway)

Ventral vs. Dorsal Striatum

ventral: reward, appetitive motivational and affective states; aversive motivational/affective states; medium spiny neutrons (motivation: reduced MSN activity, aversion: increased MSN activity); dopamine encode stimuli valence; bitter and sweet both suppressed dopamine release in ventral striatum dorsal: dopamine and action (motivation and body movement); DA better than predicted, GO; DA worse than predicted, NO-GO

Marr's Approach to Vision

vision results in 3D representation of objects for recognition; primal sketch ("1D" black and white contours represenitng 3D image); 2.5D sketch (1D image with arrows indicating protruding parts); 3D sketch

Vision as Inference / Vision is Top-Down

visual perception and recognition requires feedforward and feedback processing; early: bottom-up, coarse, narrow down "types"; later: top-down/bottom-up, fine/detailed, expectations, filling in, pattern completion; feedforward: data driven and purely reflecting sensory input, going from early processing (at retina) to late processing (at anterior inferior temporal cortex); feedback: processing that goes the other way, allowing high level conceptual representations to influence processing at early areas that represent simpler visual features (corners of triangle creating illusion that there are lines connecting them)

Cognitive Psychology

we can understand the mind by observing how it performs information processing tasks

Brain Mapping

wilder penfield shows us that stimulating one part of the brain can create a strong subjective mental experience

Neurons and Levels of Analysis

CNS: attention, memory, language, etc (1 m) systems: language, default mode network (10 cm) maps: motor and somatosensory strips (1 cm)

Ebbinghaus

ability to remember is determined only by a few factors; memory treated as single thing; memory as unified, determine by how well material is learned and how long it has been

Measures

accuracy: was the response correct; response time: difference between time of response and time of stimulus on set; speed-accuracy tradeoff; response time should be greater when more stages are involved, a stage is repeated, or a stage takes longer to complete; choice response time > recognition response time > detection response time

Dopamine

acts as neurotransmitter (chemical released in synapsse for cell-to-cell communication); parkinson's occurs from a loss of dopamine neutrons; drug abuse (inc dopamine levels); rewards -> dopamine release (pleasure signal); regulates sensory motor coordination, motivational functions, mood, reward-dependent learning and memory; unpredicted reward -> dopamine activation; positive error: rewards larger than expected -> strong excitation vs. fully predicted -> no excitation; negative prediction error: rewards omitted -> inhibition

LTM vs. STM

after list, do math for 30 seconds or do nothing... filling the delay with a task gets rid of recency; fast presentation reduces encoding and consolidation time, while speeding presentation reduced primacy

Challenges with Vision

ambiguity problem: sometimes an image can be interpreted in many ways (seeing elephant and lady, 3D cubes perspective); context problem: the way we see an object or part of an image is influenced by its context (shadowing, black/blue gold/white); invariance problem: one to many (one object can produce many different images on the retina via viewpoint or distance/size) & many to one (different objects can product similar images on the retina); how? -> 2 visual systems, different purposes (recognition/categorization & acton); vision is iterative (feedforward vs. feedback); vision relies on experience based inferences

Ventral Visual Processing Stream

anterior temporal lobe: abstract, whole visual field; V1: line orientation, small RF; output of earlier processing is combined in later stages; hierarchically organized (RF in later stage encompasses smaller RFs from earlier stages & feature combinations increase in complexity and abstraction); damage leads to specific kinds of visual disorders; as information is processed along the ventral visual stream (back to front), the information that a neuron represents becomes more abstract, and receptive fields become larger

Reward vs. Aversive Conditioning

aversion learning: association of a novel taste with symptoms of illness, long delays before presenting US, long lasting aversion, advantageous paradigm for studying mechanisms of learning and memory; doesn't occur with any US paired with any US, but is constrained by biology; helps enhance survival and therefore some sensory stimuli and responses are easier to associate than others rewarding learning: increase chance that behaviors happen again, approach is UR -- prepatory behaviors (mouth movements); both involve withdrawal symptoms (aversive is to stop behaviors, rewading encourages)

Wada Test

before surgery for epilepsy; anesthetize one side of brain; what happens to language and motor function? can control one of his arms, loses some speech (1 hemisphere); loses control of other arm, can still speak (other hemisphere); tells us language depends on left more than right hemisphere, the brain is contralaterally organized (right hemisphere controls left hand), and one hemisphere can function when the other hemisphere is alseep

Brain Structures

brain is more than just the cerebral cortex; corpus callosum, basal ganglia, hippocampus, amygdala, thalamus

Early Selection Model

broadbent says attention blocks the identification of irrelevant stimuli (sensory store | -> identification (one at a time) -> working memory ->)

The Mind-Body Problem

cartesian dualism, rigid distinction between 2 types of substances: material (extended) and mental (thought), the "seat of the soul," the mind

The Brain

central nervous system: frontal lobe, parietal lobe, temporal lobe, occipital lobe, pons, cerebellum, medulla oblongata; cortex: white mater (axons) and gray matter/cortical sheet (cell bodies); gyri are squiggles, sulcu are defining lines; broadmann area map: dorsal (top), anterior/rostral (front), posterior/caudal (back), inferior/ventral (bottom), lateral and medial

Neural Transmitters

chemicals that transmit signals across a synapse from one neuron to another 'target' neutron

The Emergence of Cognitive Science

chomsky, tolman, and turing proved the mind isn't just learned behavior; if the mind isn't just learned behavior, then what is it? what makes something a clock? dennett says a clock is a clock because of its function

Chomsky's Challenge to Skinner from Linguistics

claim: behaviorism (operant conditioning) can't explain language; language acquisition is innate and evolved (critical period [early in life...hard to learn language later in life], effortless, poverty of the stimulus); universal grammar: innate set of rules that constrain language acquisition (syntax isn't random); language is productive (saying something you've never said before)

Marr & Poggio's Levels of Analysis

computation (what problem are we trying to solve? inputs/outputs?) -> algorithm (how the mind does it..) -> implementation (the physical act of doing it...); how is it physically realized? hardware; how does the brain recognize words? complex and incomplete

Fields Involved with Scientific Study of the Mind

computer science, psychology, neuroscience, linguistics, philosophy, and anthropology, paleontology, sociology, math, engineering, etc.

Phineas Gage

damage to the medial frontal cortex; basic cognitive, perceptual, and motor functions in tact; marked personality changes; planning and decision making problems

Important Concepts in Experimentation

design: independent vs. dependent variable(s); control and avoid confounds; inference: reliability, validity (eg. scales and radar guns), causality

Perceptual Processing

detection task: clap when you see a picture; simple recognition task: clap when you see a cat; choice task: say whether the flowers are pink or red as soon as you see them

Late Selection Model

deutsch & deutsch say attention filters what gets into explicit memory (sensory store -> identification | -> working memory ->) all items!

Retina

early visual pathway: retina codes locations and features (fovea); cones: specific wavelengths (colors), more in fovea; rods: greater light sensitiviy, more in periphery

Bits

entity that can take on two, equally likely values, they can be combined to represent anything; # of bits = amount of information

The Debate

evidence for both early and late selection, but which is right? perceptual load theory: what matters is how difficult selection is -- early selection happens when perceptual load is high and late selection happens when perceptual load is low

Empirical Approaches to Studying the Mind

experiment -> data -> theory -> (cycles); how does information processing change at the limits of our abilities? see when it breaks down

Modularity

franz: lesion data don't have to mean that functions are localized or that the brain is modular lashley: amount, rather than location, of cortical lesions is hat matters most for relearning mazes function of a brain region may not be purely hardwired

A Challenge from Turing's Mathematics

halting problem: when do you stop looking for a solution, is there a mechanical way to decide? turing machine: a hypothetical machine that uses algorithms to mechanically compute solutions; physical way of solving problems that have a solution; algorithms are finite, recursive, and predictable; universal turing machine: a turing machine that can simulate any other turing machine; math and logic problems solved using relatively simple, physical means

Interference

how do people choose what's relevant and which actions to take? how well can they do this? neutral (block of blue color), congruent (word blue with blue color), incongruent (word red with blue color); accuracies: neutral=90, congruent=95, incongruent=70; response times: neutral=600, congruent=500, incongruent=1000

Problems with Cartesian Dualism

how does the mind interact with the body? how could a mind that occupies no space be tied to a single body? the mind depends on the body, physical things can do mental things

2 Central Questions

how is information coded in our minds and brains? how do we divide what the mind does into smaller tasks and sub-tasks? what are the "channels"?

George Miller

how many bits can a channel handle? does it depend on the type of information? recoding; try to remember... short term memory is limited to 7 +/- 2 chunks; different tasks also limited to just a few bits *now thought to be <4

Problems with Identity Theory

if two entities don't have the same brain (human vs. cat), then it's necessary that they don't have the same mind (experience the world differently), Leibniz's law and species chauvinism; thoughts of afterlife

Leibniz's Law

if x and y have all the same properties, then x and y are identical; if identity theory is accurate, then minds and brains are the same, but intuitively there seems to be some difference in that it feels reasonable to talk about a belief I hold as being true or false, but it isn't necessarily as reasonable to talk about a brain state (eg. arrangement of neurons, chemicals, etc.) as being true or false. what does is mean to say a brain state is "false"? but if we want to identify brains and minds, then beliefs are just brain states, so we shouldn't have any trouble identifying them

Multi-store Model of Memory

input -> sensory store (iconic: visual or echoic: auditory) -[encoding]-> STM (rehearsal) -[consolidation]-> <-[retrieval]- LTM

The Information Processing Approach

input = stimulus, output = response, algorithm = method that transforms the input to produce the output; information theory (shannon): 3 stages of communication are encoding, transmission, and receiving; Miller says we can study the mind by looking at how it handles information; cognitive systems are like information channels; limited in capacity

Memory

is best for first and last items; recency effect reflects short term memory (STM): rehearsed in STM until the test, effortful; primacy effect reflects long-term memory (LTM): can be moved to LTM before they are lost, takes time

Short-term (working) Memory

keeps currently relevant information available for use

Aphasias

language disorder caused by brain damage; broca's was nonfluent, but language comprehension was in tact and wernicke's was fluent, but contains little meaning

Split Brain Research

left eye sees right visual field object and right eye sees left visual field object; some functions appear to be lateralized

Episodic Memory

like traveling back in time; specific information about event's context

Modularity vs. Distributed Processing (Integration)

localization is found when a localized approach is taken (stroke and lesion studies -- damage to specific structures, electrical simulation studies), but "the brain doesn't work that way" and rather works through distributed processing (integration): different areas of the brain are interconnected and they interact in order to process informtion

How to Study The Mind

look at the min and examine its process (used in linguistics), engineer the mind (after knowing what mind does, researchers build a system to do similar things), and experimentation (to see if the mind performs certain functions, and if so, how?)

Jennifer Aniston Cells

medial temporal lobe neurons code invariant, abstract, conceptual features of the image

Lashley's Search for the "Engram"

memories are disributed across the brain; equipotentiality: any part of the brain can carry out any function; law of mass action: degree of impairment is proportional to the amount of tissue lost, not where it's located

Semantic Memory

memory for facts not tied to a specific event

How is the Mind Structured?

module: domain-specific system that performs a simple, determinate task (eg. word reading module? eye detection module?); domain general system: can process many types of input for different kinds of tasks; akin to an algorithm: take specific input, use set process to give specific output

Challenges with Studying The Mind

nature vs. nurture, top-down vs. bottom-up, goal-driven vs. data-driven, conscious vs. unconscious, and controlled vs. automatic; *introspection*: what we think we know of our mind may not be true (optical illusions)

Primary Visual Cortex

neurons in V1 code edges; selective for location and orientation; tuning curve shoes us that output is noisy and present for multiple orientations (bell curve, stimulus orientation on x-axis, neural response on y-axis, with mean 0); columns: neurons responding to different orientations are organized in columns

Classical (Pavlovian) Conditioning

neutral stimuli can trigger reflexes if they are repeatedly paired with aversive/appetitive stimuli; before conditioning (unconditioned stimulus and response -- dog being presented with hot dog, dog salivates) & after conditioning (conditioned stimulus and response -- dog salivates when light turns on, knows hot dog will follow); claim: fear can be learned; reflexive responses are triggered by things that have been paired with reinforcers; generalization: Albert became afraid of things that were like white rats (white, furry, small)

Neuron

not just passive relays, they detect signals, communicate, and compute; presynaptic cell with dendrites (fingers) has chain like connection consisting of axons (in between) and the myelin sheath (marshmellows) which sends signal the synapse of another neuron which becomes the postsynaptic cell

Biased Competition Theory

objects compete for receptive fields; attention pushes the competition toward goal-relevant objects

Skinner (1957) Verbal Behavior

operant conditioning can explain language; discriminative stimulus -> behavior -> outcome (and outcome -> behavior); discriminative stimulus = audience presence or speech; behavior = vocalization/writing; outcome = observed audience response; claim: even the most complex human behavior can be explained by reinforcement learning

Species Chauvinism

partisanship on behalf of one's species, the notion that humans are elevated and unique in some way that puts us above and beyond all other organisms; the belief that we have unique experiences of the world because the way our brain is, and that no other animal can have the same experiences because they have different brains

Pavlovian vs. Instrumental Learning

pavolvian: a neutral CS is paired with an US (emotionally salient event), after 1 or more pairings, CS predicts the US, presentation of CS alone elicit a conditioned response instrumental: animal learns the relationship between a behavior and an outcome (lever pressing -> reward or punishment)

Functions of the Mind

perceive and attend, represent, conceptualize, learn and remember, problem solve, act, communicate, and predict

Folk Psychology

perceptual experience is accurate, detailed, and remembered veridically

Amygdala

12 sub nuclei (lateral and central are crucial); processing of emotional stimuli (associated with fear); interconnected with cortical/sensory processing regions (emotional memories storage); reward processing, positive emotion and attention (activation when presented with positive stimuli and activation during conditioned appetitive and aversive tasks)

Information Theory

3 stages of communcation: encoding, transmittion, receiving; anything can be coded if you know the rules; communication is potentially slow and noisy

Descartes and The Mind-Body Problem

Descartes says we'd be able to tell machines from humans because they would never be able to use speech and they wouldn't act on basis on knowledge but rather a disposition of their organs

MTL vs. Cortex

MTL: memory for recent past, important for consolidating past events into long-term memory; cortex: memory for remote past, important for holding things like words in STM, remembering events from recent/remote past, and any kind of long term memory; for recent past, MTL connects cortical areas that were involved in encoding it

Functionalism

Putnam, "what matters is what the brain does"; Minsky, "the brain is just a computer made of meat"; Marr & Poggio's levels of analysis: computation <-> algorithm <-> implementation

Thorndike's Law of Effect

a behavior is more likely to be repeated if it results in a good outcome (and less likely if the outcome is bad); the phenomena that operant conditioning exploits

A Challenge from Tolman's Rats

a rat is put in a maze and quickly finds the delicious food pellets in the usual location; how do we account for the rat's behavior? -> behaviorism: the rat learns the sequence of behaviors that lead to reward; experiment: 3 groups (no reward, always reward, no reward then reward), all cases experienced decreased number of errors -> this is explained by latent learning

Neural Systems

a set of brain structures working together, are recruited for task performance; no brain structure works in isolation; cognitive functions are distributed throughout the brain (not randomly and some structures are critical for some functions); what parts are involved in language? lots! seeing a word results in activity in many regions across the brain; same part of cortex often pops up in different tasks; unlikely that there is an "empathy" or "attention" area

Action Potential

a short lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory; signal transmission takes time (depends on myelination); likelihood of firing depends on how close the membrane potential is to threshold (most excitable part is axon hillock, where axon leaves the cell body); when a presynaptic neuron fires, an action potential travels down its axon