PSYC 230 Exam 1

Early 1800s Cognitive Psychology

mind cannot study itself

1868 - Donders’s Pioneering Experiment

Simple reaction time (RT): how long it takes to respond to a simulus

Choice RT: how long does it take to make a decision?

Choice RT - Simple RT = one tenth of a second

1879 - Wundt’s introspection

describe sensations, first psyc lab

used it as a structured experimental method to study basic elements of conscious experience (observers exposed to stimuli and asked to report immediate mental reactions)

1885 - Ebbinghaus’s Time Course of Forgetting

Learn: DAX, QEH, LUH, ZIF

Delay

Learn again

savings = original learning time - relearning time after delay

plotted savings curve

forgetting occurs rapidly for first 2 days and then levels off

Behaviorism

Early 1900s - Watson, Skinner

can only study psychology through observable behavior

Watson’s classical conditioning

Little Albert Experiment - infant shown various objects and initially showed no fear. eventually researchers paired rat with a loud noise, resulting in infant to be scared of rat even without noise

Early 1900s - Skinner

interested in determining the relationship between stimulus and response (operant conditioning) —> rat learned to press lever to either get food or get rid of electrical shock

1948 - Tolman’s Cognitive Map

behaviorism —> cognitive revolution

trained rats to find find food in a four-armed maze

• Group 1: always turned right for reward

• Group 2: reward always at location B

Group 2 found reward fastest meaning spatial map developed

1959 - Chomsky

Argued that children do not only learn language through imitation and reinforcement. Language is innate and hardwired into brain from birth.

1967 - Neisser’s first cognitive psychology textbook

focus on vision, hearing and holding information in mind for brief amounts of time

Information Processing Approach

1954: Introduction of the digital computer

transition to the mind being described as processing information through a sequence of stages

changed the framing of research questions and answers

• stimulus response —> stages of information processing

Broadbent’s filter of attention

human brain filters out unattended sensory information based on basic physical characteristics before semantic processing occurs

early selection model - filter eliminates unattended information at the beginning of process

Atkinson and Shiffrin’s three-stage model of memory

1. sensory memory (less than 1 second)

2. short-term memory (a few seconds, limited capacity)

3. long-term memory (long duration, infinite capacity

1972 - Tulving

long term memory is not a single unified system but rather divided into separate subsystems (episodic and semantic)

Axon terminal buttons

primary output structures

Dendrites

primary input structures, receive signals

cell body

metabolic center of neuron

Neural circuit

group of interconnected neurons

Receptors

specialized neurons that respond to environmental stimuli (light, touch, physical signals)

Action potentials

electrical signals that transmit neural information down a neuron’s axon, initiating at the axon hillock

allow for communication between neurons

~1 millisecond

cause the release of neurotransmitters at the synapse

all or none principle - all action potentials are of the same strength

How is information transmitted

chemical signals (neurotransmitters)

electrical signals (nerve impulse/action potential)

Different brain areas

Single Cell Recording

recording the activity (firing) of a single neuron by inserting a microelectrode

Pros: minimizes confounding variables

Cons: invasive

Electroencephalogram (EEG)

recording the brain’s electrical activity through electrodes on the scalp

• good at recording info as it occurs

• not good at interpreting where info occurs

challenging for people with thick hair (can’t apply electrodes to scalp)

Event related potentials (ERP)

EEG applied to specific events/stimuli of interest

Magnetic Resonance Imaging (MRI)

used to examine brain structure

MRI scanner creates strong magnetic field

relies on the magnetic properties of hydrogen atoms in brain matter

• magnet causes them to orient one way

• radiofrequency current is delivered causing them to spin and then snap back to their orientation

• causes a release of energy that is measured by the scanner and can be used to produce the image

fMRI

used to examine brain function

relies on the magnetic properties of hemoglobin, a molecule in the blood that carries oxygen

BOLD signal

BOLD signal

blood oxygen level dependent signal

• indirect measure of neural activity

• measures amount of deoxygenated hemoglobin in various areas

• more deoxygenated hemoglobin = more oxygen consumption by that area of the brain = more neural activity

Why is not everyone eligible for an MRI scan?

dental and oral devices

pumps and shunts

cardiovascular devices

cosmetics and accessories (mascara, metallic hair dye)

Neuropsychology

studying people with brain damage (lesions)

Double dissociation

disadvantage: case study based; difficult to generalize

Double dissociation

patient 1 with damage to region A

• can do task x

• cannot do task y

patient 2 with damage to region B

• cannot do task x

• can do task y

Temporal and spatial resolution in each method

Hubel and Wiesel

some neurons respond to specific stimulus features such as orientation, movement, and length

Blakemore and Cooper

experience dependent plasticity: structure of the brain is changed by experience

receptive field - place where you need to be to observe neural activity

specific region of sensory space or input data that can elicit a response from a given neuron

Specificity coding

representation of a specific stimulus by the firing of neurons that respond only to that stimulus

Population coding

representation of a stimulus by the pattern of firing of many neurons

Sparse coding

representation of a stimulus by the pattern of firing in small groups of neurons

Studying neurons in monkeys temporal lobes

demonstrates population coding (not 1:1 neuron to stimulus organization) where each stimulus activates a distributed pattern across many neurons and each neuron responds to multiple different stimuli

Broca’s area

area in frontal lobe associated with langugae production

broca’s aphasia: slow, labored, ungrammatical speech

fully intact comprehension

Wernicke’s area

area in temporal lobe associated with language comprehension

wernicke’s aphasia: difficulty understanding language; fluent/grammatical speech that is incoherent

intact production of fluent speech (even if incoherent)

Prosopagnosia

damage to lower right temporal lobe (FFA)

inability to recognize faces

Frontal Lobe

receives signals from all senses

thinking/decision making

problem solving

Somatosensory cortex

parietal lobe; touch, pressure, pain

Fusiform face area

inferior (underside) temporal lobe

localized area for faces

Parahippocampal place area

medial (middle) temporal lobe

localized area for places

extrastriate body area

lateral (outer) temporal lobe

localized area for body parts

Huth et al. Movie Clip Experiment

duplicates were played to eliminate fMRI noise so that brain activity could be averaged.

human brain maps language and meaning continuously across the entire cerebral cortex —> brain also organizes information by meaning where region of brain lights up for similar concepts grouped together

Memory Localized vs Distributed Function

Short term memories vs long term memories

Episodic memory vs semantic memory

Language Localized vs Distributed Function

multiple language pathways

not just broca’s/wernicke’s areas

Looking at a face Localized vs Distributed Function

emotional expression; attention/gaze direciton; attractiveness; familiarity

Neural network

interconnected areas of the brain that communicate with one another

Structural connectivity

“wiring” of the brain

which brain regions are structurally connected via axons

Functional connectivity

which brain regions are involved in the same cognitive processes?

extent to which the neural activity in two brain regions is correlated

Visual network

vision; visual perception

Somato-motor network

movement and touch

Dorsal attention network

attention to visual stimuli and spatial locations

Executive control network

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

Salience network

attending to survival-relevant events in the environment

Default mode network

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

Sensory Receptor Cells

cells that begin the transmission of information about external stimuli up to the brain via nerve signals

Vision Perception

receptors; photoreceptors (rods and cones)

stimulus: light waves

location: back of retina

Hearing Perception

receptors: hair cells (inner and outer)

stimulus: vibration

location: organ of Corti (inner ear)

other hair cells in other parts of the inner ear contribute to balance

Taste Perception

receptors: taste receptors with microvilli

stimulus: chemicals

location: taste buds on tongue

Smell Perception

receptors: olfactory receptors with cilia

stimulus: odorants

location: roof of nasal cavity

Touch Perception

receptors: mechanoreceptors

stimulus: physical change (touch, pressure, vibration)

location: skin

skin also has thermoreceptors (temperature) and nociceptors (pain)

Nature of Perception

often rapid and effortless

• can utilize perceptual rules about the environment (gravity, continuation)

not always effortless

• sometimes there is initial uncertainty about what we are perceiving

• perception can change with additional information

• can involve a reasoning process

Inverse projection problem

a particular shape on the retina can be created by an object at various orientations and/or distances

reliance on finer detail/characteristics for similarly shaped objects

Viewpoint invariance

ability to recognize objects from different viewpoints

How can we form all these perceptions?

mix of current sensory experience and prior knowledge

Bottom up processing

processing that is driven by information received by the receptors

starts with stimulus itself

Top down processing

processing that is driven by a person’s knowledge or expectations

starts with prior knowledge/expectation

Speech Segmentation

ability to tell when one word in someone’s speech ends and the next one begins

• top down processing allows for knowledge of language to affect perception

Statistical learning

learning the probabilities that one sound will follow another in a language

• pretty baby (pre and ty more likely to be in same word than ty and ba)

Saffran et al. - infant language study

infants demonstrated top down processing via statistical learning

bi was always followed by da which was always followed by ku —> bidaku easily perceived as a word

Helmholtz’s Theory of Unconscious Inference

likelihood principle

• occurs by unconscious inference

perception as problem solving

Likelihood principle

we perceive the object that is most likely to have caused the pattern of stimuli we have received

occurs by unconscious inference

unconscious inference

unconscious assumptions, or inferences, we make about the environment

Perception as problem solving

problem is solved through applying one’s knowledge of the environment to infer what the object might be

perception occurs rapidly and unconsciously — seems instantaneous

Gestalt Principles of Perceptual Organization

wanted to understand the intrinsic principles governing perception

goal to explain the way elements are grouped together to create larger objects/concepts (proposed a set of principles of perceptual organizations)

structuralism (whole is a sum of its parts) —> Gestalt (whole is different than the sum of its patrts)

experience can influence perception but is not the key driver, minor compared to intrinsic “built in” principles

Apparent movement

illusion of movement when stimuli in different locations are flashed back-to-back

Principle of Good Continuation

points that follow a straight or smoothly curving line are seen as belonging together, and the lines are seen as following the smoothest path

objects that are overlapped by other objects are perceived as continuing behind the overlapping object

Law of Pragnanz

law of good figure/simplicity

every stimulus pattern is seen in such a way that the resulting structure is as simple as possible

Principle of similarity

similar things appear to be grouped together

tend to group objects with similar properties (e.g. color, shape, texture)

Law of Proximity

objects that are positioned close to one another are often seen not as separate parts, but rather as one coherent whole

Law of common fate

leads us to group together objects that move in the same direction

Principle of common region

elements that are within the same region of space are grouped together

Oblique effect

vertical and horizontals are more easily perceived than other orientations (slanted)

Life-from-above assumption

unconscious mental shortcut where human brain assumes illumination comes from overhead

Interposition

when one object partially covers another, the covered object comes out from the other side

Scene schema

a person’s knowledge about what is likely to be contained in a particular scene

ex) fastest to perceive bread in a kitchen

Bayesian Inference

probability of an outcome is determined by

1. the prior probability: initial belief about the probability of an outcome

2. the likelihood: extent to which available evidence is consistent with the outcome

ex) perceiving page on textbook —> use prior knowledge that books are rectangular and use bottom up processing stimuli to arrive to conclusion

Gestalt vs other approaches

Gestalt: perception is influenced by intrinsic organizational laws and principles (innate)

• bottom up approach

Helmholtz’s likelihood principle, regularities in the environment, bayesian inference: perception is influenced by our prior knowledge

• top down approach

possible that we could have learned gestalt principles from experience

Faces vs Greebles

fMRI study looking at activation in FFA

greeble novices vs greeble experts

greebles - beings that have same basic configuration but differ in shapes/sizes of their parts

found that FFA is not exclusively wired for human faces (can be trained to recognize greebles)

Dorsal pathway

where pathway

parietal lobe

action pathway (execute physical movements based on what you say)

Ventral pathway

what pathway

temporal lobe

lateral occipital cortex (LOC)

perception pathway

Ungerleider and Mishkin (1982)

lesioned monkeys’ brains

object discimination task - pick the correct shape, requires intact temporal lobe

landmark discimination task - pick the food well closer to the cylinder, requires intact parietal lobe

Milner and Goodale

patient DF

damage to lateral occipital complex and temporal lobe

• could not match postcard orientation (what pathway was impaired)

• could mail postcard (where pathway was intact)

• could not name or copy object

• could draw from memory

Visual agnosia

inability to recognize objects from visual perception alone (but eyes work)

Selective attention

attending to one thing while ignoring others