psych 120a midterm dis only

cognitive psych

scientific study of knowledge and mental processes

introspection

examine own conscious thoughts and feelings (metacognition)

wundt and titchener

introspection

behaviorism

study stimuli and behavior. black box, limited to inputs and outputs. is objectively measured

thorndike and skinner

behaviorism

cognitive revolution

50s. think about how to develop and test hypotheses abt mental processes

invisible processes have visible consequences

dendrite

receives impulses from other cells at synapse which are transmitted to cell body

axon

carriers electrical impulses

myelin sheath

white matter, protects axon, increases transportation speed

axon terminal

signal exits neuron through here (end)

node of ranvier

gaps b/t myelin sheath that allow faster transportation

synapse

where neurons are transferred from one neuron to another

gray matter

cell bodies, dendrites, unmyelinated axonswhi

white amtter

myelinated axons, increases speed of conduction

anterior

front

posterior

back

dorsal/superior

upper/top

ventral/inferior

lower/bottom

lateral

side

medial

middle

how is the brain categorized

in a meaningful way - info can be transferred faster if neurons are closer tgt

sensory homunculus

the more connections you have from something you use more, the larger physically that part of the brain gets

neuroimaging techniques focus

look at the brain structurally

goals of neuroimaging techniques

• volume - see which brain regions are larger/smaller

• diagnosis - various clinical differentiations

• functional associations - which regions are more/less active during a task

  • brain more active, need more resources, can measure metabolic changes

cognitive subtraction

based on logic can find 2 tasks differing in components to find effect of experimental component

PET

positron emission tomography - visualizes active brain areas via injection of tracer (radioactive substance) into blood, revealing where blood is going, showing active areas that need O

indirect measure of brain activity

PET advantage and disadvantage

adv

• relatively good spatial resolution

• can aid in diagnosis of disorders

disadv

• poor temporal resolution

• invasive (uses radioactivity)

• expensive

fMRI

functional magnetic resonance imaging - examine where brain is active during task. measures blood flow based on O signal (which perturbs local magnetic field)

indrect

fMRI adv and disadv

adv

• spatial resolution - precise localizetion

• non invasive

• widely available

disadv

• so so temporal - better than PET, worse than EEG

• expensive

• very loud

EEG adv and disadv

electroencephalography?

adv

• more direct - only one looking at neural activity directly - neurons firing

• good temporal resolution

• non invasive

• relatively inexpensive

• portable formats avail

disadv

• poor spatial resolution

• skull and brain tissue distort electrical fields

TMS

transcranial magnetic stimulation - coil on top of head, send electrical pulse traveling through skull and into brain to alter brain activity

TMS adv and disadv

adv

• safe, non invasive, temporary

• experimentally contorlled

• test necessity of specific brain regions (causal evidence)

• good temporal resolution

disadv

• relatively brief effects

• greater impact on surface cortical areas

• potential spread of activations

• not effective on deeper brain regions

resolution tradeoff

gestalt principles

how humans process info - naturally group similar elements, recognize, and simplify complex images when perceiving

template theory

for object recognition. template for everything, match input to mental template. may involve mental transformations.

problem: too many templates

RBC

recognition by components. use geons to reconstruct objects

problem: difficult to extract geons from real images, too many geon candidates, deriving structural reps can be hard, etc.

problem w/ template and RBC

no mechanism for contextual influences

shape constancy

angle viewing the shape

size constancy

adjustment for distance of an object

brightness constancy

correct perception of object regardless of actual luminance conditions

3 properties of visual perception

• shape constancy

• size constancy

• brightness constancy

selective attention

Focus on 1 task while simultaneously ignoring everything else

Dichotic listening task

demonstrates selective attention

Attended channel

shadow, or repeat what they hear

Unattended channel

told to ignore what’s going on, can report physical attributes but usually not semantic

Early selection hypothesis

• Only attended input is analyzed and perceived

• Unattended info little to no analysis and never perceived

Late selection

• All inputs analyzed

• Selection occurs after analysis 

• Only attended info reaches consciousness

3 selective attention models

• broadbent’s (early) filter model

• attenuator theory (treisman)

• late selection model (deustch & deustch)

broadbent’s early filter model

• unattended stimulus is fully ignored

• meaning of unattended ignored

attenuator theory

• treisman

• unattended msgs attenuated and attended msgs enhanced

late selection model

• deustch and deustch

• meaning of an unattended stimulus is processed

which of early or late selection hypothesis true

depends on exact circumstances

spatial attention

mechanism by which person focuses on particular position in space

attention as spotlight

beam of spotlight represents region of space youre prepared for, inside beam processed more efficiently

posner attention study

reaction times faster when appeared on side they told would appear

change blindness

• failure to notice that some aspect of a scene has changed over time

• occurs while attention is engaged in current task, but spotlighting elsewhere

inattentional blindness

• failure to notice existence of an unexpected yet fully visible item

• occurs while attn is engaged in some demanding task

endogenous control of attention

you choose what you pay attention to

exogenous control of attention

element of a scene (stimulus of some kind) seizes your attention

top down processing

bottom up processing

modal model

• atkinson & shiffrin

• Sensory registers as buffers, preventing input from overloading STM

• Bidirectional b/t STM and LTM - LTM can affect what we’re processing in STM

iconic memory

• associated w/ visual system

• no limit to amt of visual info held

• rapid decay (<1 sec)

echoic memory

serial position effect

where each word is located in a list affects likelihood of correct recall

primacy effect

more opportunity for rehearsal of words presented first

recency effect

words experienced most recently still present in working memory