Cognitive Processes Exam 1

Behaviorism

psychological perspective that emphasizes learning through observable behaviors and conditioning

Cognitivism

psychological perspective that focuses on the inner workings of the mind. Cognitivists aim to study the cause of behaviors rather than the result.

Glial cells (function)

support nervous system, guide NS development, insulate neuron axons, perform maintenance functions, and could play a role in memory

Neurons (structure and function)

dendrites, axon, myelin sheath, axon terminals; neurons communicate chemically and electrically— chemical potentials move neurotransmitters through a synapse, where they active an electrical cascade of action potentials down to the next synapse

Hindbrain

located at the top of the spinal cord, responsible for life-maintenance functions; includes the cerebellum, pons, and medulla. Cerebellum important for coordination, reasoning, sensory processing, and memory

Midbrain

foremost (rostral-most) region of brainstem; coordinates eye movements, first stop for auditory information, pain regulation

Forebrain

largest region of brain in humans, locus of most cognitive processes

Cerebral cortex

outside layer of forebrain, has convolutions on brain’s outer surface that increase surface area; gyri, sulci, and fissures

Corpus callosum

connects left and right hemispheres, useful for lateralization

Subcortical structures

thalamus: sensory relay system; hypothalamus: maintenance of homeostasis; amygdala: fear and emotions; hippocampus: memory formation (amygdala and hippocampus in limbic system)

split-brain syndrome

reveals differences in hemispheric functions, lateralization causes them to normally work together

sensory areas of cerebral cortex

receive and interpret sensory information from sense organs; primary somatosensory projection areas process touch perception

association areas of cerebral cortex

support more complex functions like ‘thinking,’ determine required actions after inputs are received; visual, auditory, and somatosensory cortexes

motor areas of cerebral cortex

send signals to spinal cord to control body’s movement; contains maps of body, larger dedicated areas means more fine motor control

What if association areas are damaged?

apraxia: disruption of voluntary motion, unilateral neglect syndrome: lack of awareness of one side of the visual world, aphasia: disruption of language

Clinical neuropsychology

lesion studies to examine the consequences of a specific area of brain damage

MRI

structural imaging of brain using magnetic fields

fMRI

functional imaging of the brain by measuring blood-flow to each brain region; good for localizing functions

EEG

recordings of the voltage changes occurring at the scalp; good temporal information

single-unit recording

electrode inserted into brain in/near neuron of interest

TMS

temporary, reversible lesions with magnetic pulses; ethical concerns

Eye structures

pupil, lens, retina

rod photoreceptors

91 million, periphery of retina, best in low-light conditions, good at detecting motion

cone photoreceptors

4.5 million, center of retina, best in high-light conditions, helpful for acuity and color perception

receptive field

small region of space that each photoreceptor collects light information from

Lateral inhibition

Detect light, lateral inhibition highlights edges by making the dark side darker and light side lighter on an edge

parallel processing

the brain processes lots of different visual features at the same time

serial processing

processing that occurs one step at a time

primary visual cortex (V1)

V1 neurons are sensitive to different orientations of lines, central vision has larger dedicated regions of V1 than peripheral vision

Dorsal stream

where and how pathway, parietal lobe

Ventral stream

what pathway, temporal lobe

double dissociation

damage to ‘what’ pathway leads to impaired object recognition (agnosia), damage to ‘where’ pathway leads to impaired space perception (unilateral or hemispatial neglect)

binding problem

Different features of the same object are processed by different areas of the brain—how do we reunite or bind those features back together into one perception?

neural synchrony

neurons representing one object’s features will all fire action potentials at the same time; since they fire at the same time, we assume they belong to the same object

Gestalt principles

similarity, proximity, good continuation, closure, simplicity

global structure vs. local features

We tend to view the whole object before we see and analyze its smaller parts and details

bottom-up processing

Object recognition is driven in part by our perception of features present in the environment; if we don’t know what something is or have no expectation, we process features and build something from there

top-down processing

object recognition is driven in part by context and our prior knowledge

efficient vs. inefficient search

search for an object when the sought object “pops out” vs. blends in and requires closer inspection

masking

covering visual stimuli helps show us what influences object processing

repetition priming

repeating a previously seen stimulus increases processing speed of the second presentation

word superiority effect

Letters are easier to recognize when they appear as part of a word than if they appear in isolation

well-formedness

our ability to detect not-real words as long as they follow the rules of the English language

feature nets

describes that feature detectors activate letter detectors which activate word detectors

bigrams

a layer between letter and word detectors that pairs letters, accounts for well-formedness

McLelland and Rumelhart’s Pattern-Recognition Model

incorporates inhibitory and excitatory connections, feedback, and within-level connections

recognition by components model (Hummel and Biederman)

model for 3D objects using intermediate-level features called geons

Faces

unique kind of object; people with prosopagnosia can’t recognize faces but object recognition is unchanged, super-recognizers can recognize all kinds of faces even if they only interacted once briefly but their object recognition is average

brain areas involved in object recognition

temporal lobe, inferotemporal cortex, occipital lobe, fusiform face area, occipital face area, superior temporal sulcus; ‘what’ pathway

Viewpoint-dependent neurons

excited by certain objects only at a particular orientation

Viewpoint-independent neurons

excited by certain objects regardless of their orientation

Orbitofrontal cortex

shows activity indicative of top-down processing!

selective attention

focusing on one input/task while ignoring others

cocktail party effect

when participating in a conversation in a crowded room, we can focus effortlessly on the conversation without being distracted by other conversations around us

dichotic listening task

different sounds played into each ear from headphones, listener asked to attend to one side. When asked to recall unattended side, cannot say what they were talking about but may report tone of voice and whether it was male or female.

Attention as a filter

attention allows through certain information for further processing, but prevents distractors from being processed

Inattentional blindness

When we are attending something, we can fail to process other information in our visual field

Change blindness

a type of inattentional blindness—insensitivity to changes in the environment

Broadbent’s filter model

early selection; both messages go into attention store, selective filter picks out attended message and that is further processed

Treisman’s attention model

early selection; attended and unattended messages go into attenuator, attended message is emphasized but unattended message still passes through weakly

Late selection hypothesis

Deutch & Deutch; attention acts after higher order processing has occurred

early vs. late selection

Evidence from EEG/ERP studies suggest quick action by attention (Early Selection); Evidence from brain imaging studies suggest attention might act on visual information as early as the lateral geniculate nucleus (LGN) of the thalamus (before higher processing areas are reached)

Biased competition theory

Desimone & Duncan; 1. The visual system receives lots of information at once—neurons representing these pieces of information compete for our limited awareness

2. Attention biases awareness towards some types of information using priming; carrot color example

endogenous spatial attention

prioritization can be a top-down decision

exogenous spatial attention

prioritization can be driven by the stimulus itself

spotlight model

information in attentional spotlight is prioritized for more processing; spotlight must move to process other things— automatically or volitionally

object-based attention

attention spreads through an attended object rather than a region of space

moving attention

attention cues can benefit processing up to 150ms, eye movements take 150-250ms to initiate and complete

overt attention

Movements of attention with movements of the eyes

covert attention

movements of attention without movements of the eyes

Influences on where we attend

our goals, interests, cultural background, and exogenous cues