Cognitive Psych

Exam 1

cognitive neuroscience

the study of the physiological basis of cognition (the nervous system and the units that make it up)

levels of analysis

a topic that can be studied in a number of different ways- each contributes to our understanding uniquely

levels of cognition

behavior

physiology of the whole brain

brain structures

neuron electrochemical processes

nerve net

a network of continuously interconnected nerve fibers (early 1800’s understanding)

1870’s __ technique helped identify individual cells

staining

noncontinuous nerve net

individual units are connected (Ramon & Cajal)

neuron doctrine

individual cells transmit signals in the nervous system (contradicts nerve net theory)

neurons

cells specialized to create, receive, and transmit information in the nervous system

synapse

space between the axon of one neuron and the dendrite or cell body of another

neural circuits

groups of interconnected neurons (which form connections to specific types of neurons)

receptors

a type of neuron that detects information from the environment (sensory intake)

cell body

metabolic center of a neuron that has mechanisms to keep the cell alive

dendrites

multiple branches reaching from the cell body to receive electronic signals (information) from other neurons (receiving end)

axon (nerve fibers)

fluid-filled tube that transmits electrical signals from cell body to other neurons (transmitting end)

neurotransmitters

chemicals that affect the electrical signals of the receiving neuron (they cross the synapse and bind with receiving dendrites)

synaptic vesicles

tiny packets containing neurotransmitters that release chemical neurotransmitters when signals reach the end of an axon

how receptors gather information

neuron receives a signal from the environment and information travels down the axon of that neuron to the dendrites of another

action potentials

electrical signals that transmit information between neurons (a wave of electricity)

resting potential

when the nerve is at rest and there is a difference in charge

as a nerve impulse passes the electrode, the inside of the fiber becomes (more/less) positive

more positive

as an impulse moves past the electrode the charge becomes (more/less) negative

more negative

do you measure amplitude when measuring action potential?

no

low-intensity stimulus

slow firing

medium-intensity stimulus

medium firing

high-intensity stimulus

high firing

increasing stimulus intensity (increases/decreases) the rate of nerve firing

increases

mind

a system that creates representations of the world so we can act on it to achieve goals

neural representation

everything a person experiences is based on representations in a persons’ nervous system

true/false: everything exists as a representation in the nervous system

true

feature detectors

neurons that respond best to a specific stimulus feature (Hubel and Wiesel- cats’ visual cortex fire in response to specific stimuli)

experience-dependent plasticity

the structure of the brain changes with experiences (kittens exposed to specific stimuli could later only perceive specific qualities of stimuli)

complex stimuli & temporal lobe

neurons in the temporal lobe respond to some complex stimuli (monkeys’ temporal neurons fired when presented with a shadow/image of a hand)

some temporal neurons respond best to

faces

hierarchical processing

progression from simple/lower to complex/higher level processing in the brain

sensory coding

how neurons represent characteristics in the environment

specificity coding

representation of a stimulus by the firing on specifically tuned neurons specialized to respond only to a specific stimulus

population coding

representation of a stimulus by the pattern of firing of a large number of neurons

sparse coding

representation of a stimulus by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent

sparse coding may be the case for __ recognition

facial

localized representation

specific functions are served by specific areas of the brain- damage to certain areas causes specific function decline

cerebral cortex

a layer of tissue (\~3mm thick) on the surface of the brain; activity in this area is associated with many functions

double dissociation

allows us to identify functions that are controlled by different parts of the brain

when does double dissociation occur?

1. damage to a part of the brain causes function A to be absent while function B is present
2. damage to another area causes function B to be absent while function A is present

(note: mutually exclusive)

damage to Broca’s area causes

loss of speaking abilities while maintaining comprehension abilities

damage to Wernicke’s area causes

loss of comprehension abilities while maintaining speaking abilities (may not be coherent)

where is Broca’s area located in the brain?

the frontal lobe; language production

where is Wernicke’s area located in the brain?

temporal lobe; language comprehension

primary receiving areas for the senses

occipital lobe

parietal lobe

temporal lobe

frontal lobe

occipital lobe

vision

parietal lobe

touch, temperature, pain

temporal lobe

hearing, taste, smell

frontal lobe

coordination of information received from all senses

Fusiform Face Area (FFA)

responds specifically to faces, damage to this area causes prosopgagnosia

prosopgagnosia

inability to recognize faces

parahippocampal place area (PPA)

responds specifically to places

extrastriate body area (EBA)

responds significantly to pictures of bodies and body parts

functional magnetic resonance imaging (fMRI)

measures neural activity by identifying highly oxygenated hemoglobin molecules

active areas on an fMRI

areas that are more active relative to resting state

central principle of cognition

most of our experience is multidimensional- even simple experiences involve combinations of different qualities

specific functions are processed by (many/one) area(s) of the brain

many

distributed neural representation in memory

memories are often both perceptual (visual/auditory) and emotional components

distributed neural representation in language

damage outside of Broca’s/Wernicke’s area can cause problems in language

neural networks

interconnected areas of the brain that communicate with each other

first principle of neural networks

complex structural pathways called networks form the brain’s information highway

second principle of neural networks

within structural pathways are functional pathways that serve different functions

third principle of neural networks

resting state

resting state

response recorded when a person is at rest and not performing any tasks

fourth principle of neural networks

networks operate dynamically (like cognition)

track-weighted imaging (TWI)

based on detection of how water diffuses along the length of axons or nerve fibers

connectome

structural description of network of elements and connections forming the human brain

structural connectivity

the brain’s “wiring diagram” created by axons that connect brain areas (very unique to each person)

functional connectivity

how groups of neurons within the connectome function in relation to types of cognition

how is functional connectivity determined?

the amount of correlated neural activity in two brain areas

functional connectivity (does/does not) = communication

does not

default mode network

decreases activity during a task, increases when there is no task

visual network function

vision and visual perception

somato-moto network function

movement and touch

dorsal attention network function

attention to visual stimuli and spatial locations/awareness

executive control network function

higher-level cognitive tasks involved in working memory and directing attention during tasks

salience network function

attending to survival-relevant events in the environment

default mode network function

mind wandering and cognitive activity related to personal life story, social functions and monitoring internal emotional states

perception

conscious experience resulting from stimulation of the senses

basic characteristics of perception

1. can change based on new information
2. has a process similar to reasoning
3. appears automatic
4. built from experience

perceptual systems are robust to noise

many objects can create similar inputs, humans are capable of whole perception despite partial sensation

viewpoint invariance

ability to recognize objects seen from different viewpoints

2 types of information used in human perception

1. environmental energy to stimulate the receptors
2. knowledge and expectations the observer brings to the situation

bottom-up processing

processing that starts with information received by the receptors (“direct perception”)

top-down processing

processing that involves knowledge/expectations (“constructive perception”)

speech segmentation

process of perceiving individual words within continuous flow of speech signal

transitional probabilities

the likelihood that one speech sound will follow another within a word

Saffran, Aslin, and Newport (1996)

learned about transitional probabilities and other characteristics of language, such as partial word stimuli

likelihood principle

we perceive what is “most likely” to occur

unconscious inference

knowledge from prior experiences with similar situations leads us to make unconscious assumptions about the environment

structuralism (“old view”)

perception involves adding up sensations (wilhelm wundt)

gestalt principles (“new view”)

the mind groups patterns according to intrinsic laws of perceptual organization (max wertheimer)

gestalt principle of apparent movement

illusion of movement perception occurs when stimuli in different locations are flashed one after another with proper timing; the whole is different from the sum of its parts

principles of perceptual organization

rules proposed by Gestalt that psychologists use to explain perceptual grouping of small elements into large units

gestalt principle of good continuation

lines tend to be seen as following the smoothest path

gestalt principle of the law of pragnanz

every stimulus pattern seen so that the resulting structure is as simple as possible

gestalt principle of similarity

similar things appear grouped together- based on color, size, shape, or orientation