psy2601 cumulative final exam

what is epistemology and its two schools of thought

the study of knowledge

2 schools: empiricism and rationalism

rationalism (school of thought within epistemology) believes what and that what is the source of knowledge

believes that reason is the source of knowledge

senses distort

we are born with knowledge and gets revealed through analyzing logic

empiricism (school of thought within epistemology)

believes that experience is the source of knowledge

senses are how we learn

we are born with ability to understand eventual knowledge we gather

philosophy vs. psychology

philosophy studies knowledge

psychology EMPIRICALLY studies mental structure

structuralism (approach to psychology) assumes what and uses what as a method

assumes the mind is a complex structure of basic elements (periodic table)

uses introspection as method to describe and interpret elements

what challenges the THEORY of structuralism

gestalt psychology

what does gestalt psychology (counter to structuralism theory) believe

the whole is greater than the sum of its parts

human mind actively organizes what it processes… produces output different than stimulus

goal cannot just be identifying structure

why is introspection a problematic and not empirical method

it is subjective

what does methodological behaviorism believe

that mental events cannot be studied objectively, rejecting introspection

there is still a black box between stimulus and response

behaviorism claims

to empirically study psychology = must limit itself to observable

stimuli and responses

radical behaviorism believes

not only are mental states unobservable = they do not exist

core assumptions of cognitive psychology

internal mental states are real

changes in behavior reflects changes in mental states

changes in mental state occurs through mental processes

THUS = cognition (mental state/processes) can be studied objectively by studying behavior

general strategy of cognitive psychology

stimulus is objectively measurable and manipulable

the mental process is inferable

response is objectively measurable

• manipulate stimulus

• infer mental process

• measure response

methodological behaviorism vs. cognitive psychology

m: focus on external behavior, mind is black box and unstudyable

c: focus on mental processes, mind is essential to understanding behavior

both are empirical, believe experience shapes behavior

a measure is invalid if

• there is no association between measure and mental construct

• it is biased

a measure is unreliable if

• the association between measure and mental construct is too loose

a measure is reliable if

the measure is consistent

a measure is valid if

if reflects the construct

do measures need to be both valid and reliable?

why?

yes

our inferences can be no better than our measures

two overall measure types used to study cognition

behavioral measures (response measure)

neural measures

does cognitive psychology assume that cognition is embodied within the brain/nervous system?

yes

common neural measures used to study cognition (2 neural and 2 metabolic)

measuring neural activity

EEG

ERPs

measuring metabolic activity indirectly related to neural activity

fMRI

PET

event related potentials (ERP)

changes in electrical activity associated with a specific event

time-locked

fMRI and PET use what

what are they measures of

use subtraction logic

measures of relative metabolic activity across conditions, which is indirectly related to relative neural activity across conditions

are neural or behavioral measures better

neither is better; both require scrutiny regarding validity and reliability

occipital lobe main function

visual perception

temporal lobe main function

auditory and high level visual perception

language

parietal lobe main function

spatial attention

frontal lobe main functions

problem solving

movement

social interaction

amygdala controls

emotions

hippocampus controls

memory

thalamus controls

sensory processing

capgras syndrome

an object with emotion attached to it (i.e. mom) is no longer recognized as having that emotion attached due to damage to amygdala; only visual input is received

two-pathway explanation of capgras syndrome

1. visual input is recognized by temporal lobe and identified as a face you know

2. limbic system (amygdala) generates an emotional response (i.e. warmth)

BUT

in capgras = pathway 2 is disrupted

SHOWS

that neural and cognition are intertwined

signals WITHIN neurons are _____ and use _____

electrical

action potentials

signals BETWEEN neurons are _____ and use _____

chemical

neurotransmitters

firing rate

how many action potentials to trigger travel of signal

journey of signal within and between neurons

action potential travels along the axon to axon terminals and triggers release of neurotransmitters

neurotransmitters cross the synaptic cleft to the next neuron’s dendrite

excitatory synapse

increases likelihood that postsynaptic neuron will fire

inhibitory synapse

decreases likelihood that postsynaptic neuron will fire

how are ERPs measured from overall EEG

averaging segments from EEG that are time-locked to repeated event; the ERP is that constant response which clearly emerges

FFA is active during face perception … does that mean the FFA is DOING face perception?

what type of relationship is this

why not

no

correlational

because we would need to take out part of brain that is active to have evidence which is not doable

TMS can be used to test _______ claims about function of different areas

how?

causal

applies magnetic field outside of skull to excite or disrupt neurons in a certain area to decide if it is necessary for x,y,z function

general function all sensory systems serve

establish internal representations of external world in order to interact with it successfully (successful = stay alive and reproduce)

rods

function

concentrated WHERE on retina

black and white/bad at details/dim light

peripheral

cones

function

concentrated WHERE on retina

color/good at details/bright light

middle (fovea)

receptive field definition

part of world a sensory neuron is sensitive to

what cells have receptive fields

ganglion cells

what codes for the presence of edges

the firing rate of retinal ganglion cells

retinal ganglion cells are ____ detectors

edge

how do ganglion cells detect edges

ganglion cells respond best to light contrast between center and surround, so they are sensitive to edges

2 main types of ganglion cells

• On-center / Off-surround cells

  • Light in the center → increases firing (excitation).

  • Light in the surround → decreases firing (inhibition).

• Off-center / On-surround cells

  • Light in the center → decreases firing (inhibition).

  • Light in the surround → increases firing (excitation).

V1

first cortical area receiving visual info

if a V1 cell codes for a vertical edge = what is its preferred stimulus

if represented on a tuning curve…

vertical orientation of a bar that indicates a vertical edge

if represented on a tuning curve with 90º in middle, big peak in the very middle at that 90º orientation and lesser at 60º and 120º and none at 0º

do all neurons have receptive fields?

i.e. cones, rods, ganglion cells

yes

“perception involves not just encoding stimuli but also interpreting them” means WHAT using face-vase picture

you detect the edge and black and white portions (encode stimuli) but then must ASSIGN edge to either face or vase (interpret stimuli) to see varying figures

stimulus on retina has no change (encoding) but perception flips (interpretation)

similarity (principle of perceptual organization)

group similar things alike

proximity (principle of perceptual organization)

perceive things close together as groups rather than individual items

good continuation (principle of perceptual organization)

tend to see continuous whole rather than two parts

closure (principle of perceptual organization)

we have bias towards perceiving complete figures rather than incomplete ones

simplicity (principle of perceptual organization)

tend to interpret form in simplest way possible

size constancy

size perceived as constant across distances, and thus across retinal-image sizes

shape constancy

shape is perceived as constant across angles, and thus across retinal-image shapes

perceptual illusions are ________ of sensory input

systematic misinterpretations

what do illusions help us understand

how the cognitive system processes sensory information

how do illusions relate to size and shape constancy

brain misinterprets cues it uses in real life and does too much to correct in these images, distorting our perception of shape or size

why is object recognition a challenging information processing task?

the same features can be recognized as different objects - THE vs CAT

different features can be recognized as the same object - chair views

ventral processing stream starts at V1 and goes to ________

temporal cortex

what kind of information processing does the ventral stream do?

WHAT - object recognition

dorsal processing stream starts at V1 and goes to _______

parietal cortex

what kind of information processing does the dorsal stream do?

WHERE - spatial location/depth/etc

damage to what processing stream often results in agnosia (impaired object recognition)?

ventral processing stream

agnosia

impaired object recognition

3 types of agnosia

apperceptive agnosia

associative agnosia

prospagnosia

apperceptive agnosia

patients get features of objects BUT can’t put them together properly in a recognizable representation

apperceptive agnosia shows us that

objects are represented as combinations of basic features

associative agnosia

patients form objects, but cannot connect those objects with their semantic meaning

associative agnosia shows us that:

recognition requires associating perceptual representations with stored representations

prosopagnosia

category-specific loss

patient is unable to recognize faces even though other objects are recognizable

prosopagnosia shows us that:

recognition consists of multiple separable systems; these may function differently

how are words represented in a simple feature network?

feature detectors respond to simple elements; activate to trigger letter detectors

letter detectors activate to trigger a word detector

if word detectors receive enough activation; we recognize a word

within simple feature network

frequency and priming effects show:

objects that are more frequent or are primed are recognized more easily

how do frequency and priming effects occur within a simple feature network?

detectors activated more often (FREQUENT) or activated recently (PRIMED) are already partially activated

this require less additional activation to reach threshold and trigger next detector

do simple feature networks predict the effect of well-formedness (words following rules of language vs. not following language rules)

no

how does adding a bigram layer help with word recognition when the input is poor?

these detect letter pairs that are frequently grouped together in your language and need a weak input to fire; we recognize possible words from possible strings easier

how does adding a bigram layer cause recognition errors?

• ex: if CQRN is presented briefly = we recognize it as CORN

weak signal is being sent to bigram detectors (receiving strong signal from first bigram letter; receiving weak signal from second bigram letter)

BUT weak signal for second letter is enough to trigger a well-primed bigram detector to lead to mistakenly recognize a word for another (more frequent/primed) word

within object recognition, there is a tradeoff between ______ and _______

efficiency

accuracy

how does adding inhibitory connections and feedback increase the range of phenomena a feature network can explain?

inhibition - sharpens and limits activity

feedback - adds context and expectation

word superiority effect

we can perceive a given letter more easily when it is presented within a word rather than alone

object invariance (ability to….)

the ability to recognize objects regardless of point of view

what is the problem of invariance with regard to object recognition

*incorporate: template theory of object recognition

invariance claims that the same object can produce very different retinal images which we can identify, but template theory would demand a separate template for each variation

we would need infinite templates for every object (ex. fonts)

recognition by components (RBC) theory of object recognition

RBC is a structural description theory

the cognitive system takes the images as input and identifies component parts to then represent the object as a set of parts + their spatial relations

how does recognition by components (RBC) theory of object recognition handle the problem of invariance

*incorporate viewpoint-invariant properties in explanation

RBC solves the problem of invariance by assuming the component parts are distinguishable from each other on the basis of viewpoint-invariant properties (parts are recognizable regardless of viewpoint = whole objects are stable and can be recognized regardless of viewpoint)

recognition by multiple views theory of object recognition

we have an idealized representation of an object class; stores many images of an object from many different POVs and experiences

*elaborated template model

how does recognition by multiple views theory handle the problem of variance differently from RBC?

RBC claims we don’t have any sort of template, we put together parts to make objects

multiple views claims we have a sort of loose template for object classes

part-based processing vs. holistic processing

part-based: recognition depends on parts themselves

holistic processing: recognition depends on representation of relations between parts

how does the thatcher effect suggest that face perception relies on holistic processing?

weird face looks normal when upside down because we are processing with part system…. when it is right side up like other faces = looks weird because we are now processing holistically

face recognition is “special” because it is more realistic, which reflects our ______ with faces; FFA is actually reflecting ______ because we get faster at identifying familiar things

expertise

inversion effect

evidence that faces are processed differently;

face recognition is impaired more by inversion than non-face object recognition is impaired

william jones quote captures idea of _____ attention

selective

mind possesses one out of several possible objects/thoughts