cognition quiz 1

chapters 1-4

rationalism

descartes, all knowledge is innate and must be found through questioning

empiricism

knowledge is gained from experiences

Donders

first psych experiment, reaction time vs. choices, used behavior to infer something about cognitive states

Ebbinghaus

memory of nonsense syllables, created savings curve, less savings = less memory, decay = decrease in savings which is used in experimental psych

structuralism

Pioneered by Wundt, analytic introspection, change experience to measure impact on inner concious, controlled experiments

Wundt

First psych lab, radical empiricist, believed all experiences are made of percepts, nothing but inner experience

Functionalism

function of behavior as the result of holistic mind, what role behavior plays in our lives, inspired by natural selection, consciousness is a continuum

William James

attention = spotlight, wrote foundational book Principles of Psych

issues of structuralism

Extremely variable, unable to directly observe thoughts objectively, created behaviorism in response

behaviorism

Watson, response to structuralism’s issues, psychology is a science that should focus on observable behavior rather than guessing about mental processes, linked behavior to environment

classical conditioning

appetitive conditioning, classical conditioning relies on outcome not being related to behavior (appetite is created for the positive outcome through a reaction)

Watson’s issues with conditioning

Pavlov’s paradigm does not mention internal sensations, focused instead on behavior through fear conditioning, Little Albert experiment with rat/loud noise, focus on association between stimulus and response

Skinner, operant conditioning

radical behaviorism, claimed all behavior is stimulus-reward based, mental states exist but don’t matter, must discover laws relating stimuli to behavior

Skinner’s box

rats press level for food (positive reinforcement), shocked when negative choice madet

what does skinner’s experiment tell us

• precursor to reinforcement learning

• positive result = repeated

• negative results = avoided

tolman’s cognitive maps

rats create spatial maps, learn to navigate using reorientation, proved that mental processes do matter to spatial awareness

Skinner’s verbal behavior

Said that children learn language through seeing, result of environment

Chomsky’s criticism

language is innate, a product of the mind as we can create original sentences, and many structures are similar across languages

• there is no theory of cognition in behaviorism

• explanations in behaviorism are unobserved and theoretical

cognitive revolution

paradigm shift from behaviorism to information processing theory

causes of cognitive revolution

computers, Chomsky critique of behaviorism, conferences at MIt and Darthmouth eg. 7 plus or minus 2 bc/ inputs have to be processed in order for limits to exist

types of experiments

• controlled experiments

• psychobiological research

• correlational research

psychobio methods

• post mortem examination of brain structures

• measure deficits in people with lesions

• observe brain in healthy people with controlled settings

non-dualistic approach

mind = body, everything is physical

Marr’s idea of vision

computational theory → representation/algorithm → implementation, implementation is fundamental to cognition

neurons seen through

Golgi stain, only affects <1% of neurons

nerve net theory/reticular theory

interconnected network of cells, continous mass of tissue

neuron doctrine

• Ramon y Cagal showed using golgi staining gaps between neurons

• nervous system composed of discrete cells (neurons), info goes from dendrites → cell body → synpases, have specialized functions

• comparison to previous whole function by tissue coming together

• implied specialized neurons that were basic information processing units

neuron function with AP

• neuron rests at -70 mv

• depolarization makes it less negative

• AP fires

• repolarized

• hyperpolarized

Action potential

depolarization when received input→ repolarization, lasts around 1 ms, refractory period before returning to rest,

• do not change shape along axon (adrian)

neurotransmitters

• released at the synapse by neuron 1

• accumulate at synaptic cleft create postsynaptic potential

• axon sums alls the PSP

• if passes threshold —> AP created

signals within neurons are

electric

signals between neurons

chemical

how do neurons relate to sensation

Adrian showed the more closely crowded the rate of firing is, the more intense the sensation

gray matter

cell bodies and dendrites

white matter

axons

gyrus

top fold of cortical surface

sulci

bottom grooves of cortical surface

4 lobes

frontal, parietal, occipital, temporal

double dissociation paradigm

• lesion in one area = deficit in speech production

• lesion in another = different deficit

• used to study many different kinds of psych

• showed functionalism by relating structure to a function of the brain

theory of faculties

Gall/fodor: tried to explain why people see the world differently

• mind is separated into faculties that each do something different

• vertical faculties: domain-specific, eg. language part executes language faculty

• horizontal faculties: domain-general, defined by effect

associationism

based on the Hebbian principle, cells firing together are wired together, against the idea of innate cognitive architecture

empiricist epistemology

only faculty is the ability to form associations because they form our understanding of people

broca’s area lesions

frontal lobe damage, aphasia with speech issues and some comprehension issues

wernicke’s area

temporal lobe damage, difficulty understanding sentences. incoherent but fluent speech,

Broca and wernicke’s area

disproved cortical equipotentiality, proved that the brain is an inseperable whole

EEG

• Electrodes placed in cap on scalp

• neurons needs fire together and perpendicular to the cortical surface

• must have same alignment to avoid cancelling

• better for measuring gyri than sulci

• graph shows time in ms vs. potential in microvolts

• AP signal at 1ms

MEG

• same concept as EEG

• records the magnetic fields produced by electrical currents

• same temporal resolution, better spatial resolution than EEG

PET

• positron emission tomography

• measures a radioactive substance at different locations

• temporal res depends on the half life of the substance

• doesn’t capture AP

MRI

• brain activity measured using a huge magnet

• neurons must be perpendicular to surface

• does not capture AP

• measured in voxels (3D slice of images)

• structural = grayscale images of brain anatomy for lesions

• functional = measures neuronal activity over time through changes in blood flow, across time

BOLD signal

• fMRI works by detecting oxygen level changes

• blood oxygen level dependent —> measures ratio of oxygenated to deoxy

• more activity = more oxygenated blood

• initial dip → peak → post stim undershoot → return to baseline

single neuron representations

• visual system showed neurons are feature detectors (specific to orientation, mvmt, etc.)

• Hubel and Wiesel established single cell recording in cat visual cortex

• parallel processing — multiple parts doing diff things

how do single neurons build to experience

• shown through selective rearing

• neurons were developed FOR the env. stimuli, showed neural plasticity that depended on experience

• example of sensory coding because response maps to a property of environment

neural code

• add together neuronal activity to create population level response

• 3 different ways to encode info

  • specificity — one neuron responds to one stim, each new item = new neuron

  • population: pattern across pop encodes info, makes the variance meaningful

  • sparse: some parts of pop. respond, not all

localization/specialization

• broca/wernicke: specalized for language

• match areas to brain functions

• Fusiform Face Area matched w prosapagnosis

distributed representation

• emotion, recongition, memory, visual processing

• multiple areas work together to process a stimuli (eg. face)

neural networks

• help us understand the distributed representations

• interconnected areas can communicate with each other

• structural connectivity — physical white matter connected with track-weighted imaging shows distributions of representations

task vs resting state fMRI

• resting state shows functional networks that are active when we’re at rest

• task A vs. task B one w/o cognitive activity, find regions more active

functional connectivity

• time based relationship between different brain regions

• what fires at what time in the task

default network

• not a specific task, actually gets less active when specific tasks 

• maintains the brain at rest

• mind wandering

• nodes are very connected to one another at rest

perception

experience of sensations undergo cognitive transformations

sensations

input to the senses, gather info by finding stimuli

visual processing flow

• light enters retina photoreceptors

• convert from light → electrical signals

• signals → visual cortex, V1 = door that everything goes through

• V1 goes to extrastriate cortexes (V2 and beyond)

• 1 neuron = 1 feature detector (eg. orientation)

hierarchical processing

• V2 more complex than V1, V3 more complex than V2

• V2/V3 = edge and contours, motion parts

• V4 = color and shape

• V5 = whole motion

double dissociation in visual processing

• temporal lobe lesions: deficits in object discrimination

• parietal lobe lesions = deficits in landmark discrimination

dorsal stream

• where pathway

• parietal lobe

• relatively fast

• viewer centered

• across retina

• helps spatial awareness

pathway of dorsal streams

V1 → V2 → V5 → posterior parietal cortex

ventral stream

• what pathway

• what am I looking at — recognition

• relatively slow

• foveal

• detailed sensitivity

pathway of ventral stream

V1 → V2 → V4 → inferior temporal cortex

how do we hear frequencies

• pressure changes at a frequency

• creates sound waves

primary auditory pathway

• locations in the basilar membrane vibrate

• info goes to olive

  • lateral olive: differences in sound levels between ears

  • medial olive: time difference between ears

• analysis occurs before A1

solving the inverse projection problem

• viewpoint invariance, blurriness

• likelihood principle: we infer the most likely cause of the stimulus

rods useful for

black/white, night vision

cones useful for

color and fine detail, conc in fovea

visual processing lobe

occipital lobe

auditory processing lobe

temporal lobe

basilar membrane

different locations on basilar membrane = vibrate for different frequencies (pitches)

Locations of A1

Superior temporal lobe, heschi’s gyrus

lateral superior olive

Compares sound level differences between two ears

medial superior olive

differences in when sound reaches each ear

Why does location get processed before A1

brainstem analyzes timing and loudness differences before signals get to auditory cortex

Heimholtz theory of unconcious inferences

perception is based on unconcious assumptions about the environment

likelihood principle

we perceive object most likely to have caused the sensory input

Helmholtz explanation of perception

Brain combines past experience and environmental assumptions to infer most likely objects

Gestalt psychology

perception is organized into wholes, not separate sensations, whole is different than the sum of its parts

Gestalt grouping rules

principles determining which elements in an image belong together

Law of simplicity/pragnanz

Simplest organized patterns

figure ground organization

brain separates a main figure , and background

good continuation

elements forming smooth lines or curves belong together

similarity gestalt

similar looking elements are perceived as being grouped together

closure gestalt

brain fills in missing info

Gestalt vs. Helmholtz

H: learned assumptions and inferences based on experiences

G: built in organizing principles

Bayseian inferences

• perception is prior knowledge x current sensory input

• prior = top-down info

• likelihood = bottom-up

• informed by semantic and physical regularities

how does baysian inference reframe perception

• perception - probability based

• brain chooses the most probable interpretation given prior knowledge and sensory evidence

bottom up

sensory input → complex perception (eg. vision, individuals letters and then using them to form a word)

top down

driven by prior knowledge/expectations (eg. recognizing letters when they’re in real words)

Wheeler showed faster and better recognition in words

McGurk effect + what does it represent

• perception combines info across senses

• conflicting visual/audio input changes what sound is perceived

• shows bottom up bc/ we use what input we hear to form a perception of the sound

physical regularities

• physical patterns in the environment that create perceptions

oblique effect

• vertical/horizontal orientations easier to percevie than angled orientations

light from above heuristic

• brain assumes light comes from above

• impx whether a surface is raised or indented

semantic regularities

• regular patterns about what objects appear in certain scenes

• what functions do they have - eg. book in library vs. book in studio