Cognitive Psychology Exam 2

memory

process involved in retaining, retrieving, and using info about stimuli, images, events, ideas

sensory memory

retention, for brief periods of time, of the effects of sensory stimulation

short term memory

system involved in storing small amounts of information for brief period of time (15-20s, or 10-15s)

• Subjects are presented with stimuli and following a delay asked to report as many stimuli as possible

Atkinson and Shiffrin model of memory

Input → sensory memory → short-term memory →← long-term memory

• rehearsal (a control process) flows in at short term memory

persistence of vision

continued perception of a visual stimulus even after it is no longer present

Why is fading (1s) sensory trace more useful for everyday perception compared to a more persistent trace (5s)?

Why is fading (1s) sensory trace more useful for everyday perception compared to a more persistent trace (5s)?

it prevents our minds from becoming overwhelmed by a chaotic backlog of outdated information

sensory store

the initial memory system in psychology that briefly holds vast amounts of incoming environmental information from our senses—like sight, sound, and touch—for a fraction of a second

Sterling’s (1960)

• subjects saw avg of 82% of all letters but were unable to report them because they faded as initial letters were being reported

  • sensory memory registers all/most information that hits our visual receptors, but information decays within less then a second

iconic memory

ultra-short, high-capacity sensory register that briefly holds a visual image after a physical stimulus disappears

echoic memory

auditory form of sensory memory that briefly holds raw sound data in the brain for about 3 to 4 seconds

recall

subjects are presented with stimuli and following a delay asked to report as many stimuli as possible

proactive interference

information that was learned previously interferes with learning new information

• old learning interferes with new learning

retroactive interference

new learning interferes with remembering old learning

how many items can be held in STM?

• Miller (1956) avg is 5-9 items

• Luck & Vogel (1997) say 4

• fewer items can be held in visual STM

digit span

number of digits a person can remember

chunking

small units like words can be combined into larger meaningful units like phrases, or even larger units like sentences, paragraphs, stories

How does chunking let us "cheat" the capacity limit of STM? Is chunking increasing capacity,

or just changing what counts as one item?

Chunking does not actually increase the physical capacity of your short-term memory (STM); instead, it redefines what counts as a single item.

Baddeley and Hitch (1974)

proposed a new term to replace STM: working memory

• found that subjects can hold numbers in the mind while reading a short passage and can still recall the numbers and passage content

working memory

limited capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning

• mental math and holding a conversation involves/storing info in memory and processing info

Baddeley’s working memory model

Phonological loop overlaps with central executive which overlaps with visuospatial sketch pad

phonological loop

verbal and auditory information

visuospatial sketch pad

visual and spatial information

phonological similarity effect

confusion of letters or words that sound similar (b & d)

word length effect

occurs when memory for lists of words is better for short than long words

articulatory suppression

subjects prevented from rehearsing by repeating an irrelevant sound like “the, the, the…”

• reduces rehearsal advantage for short words

visual imagery

creation of visual images in the mind in the absence of physical visual stimulus

Shepard & Metzler (1971)

showed subjects a pair of cubic images and asked to decide whether the objects were same/different

• when object was rotated 40 degrees, it took 2s to decide that a pair was the same shape but for 140 degrees it took 4s

• Mental rotation: rotating an image of an object in the mind

central executive

attention controller

• determines how attention is focused on a particular task, how it is divided between two tasks and how it is switched between tasks

patients with frontal lobe damage…?

have problems controlling attention

• perseveration

• as long as rule is consistent, subjects with frontal lobe perform fine

  • when rule is switched, they continue following the old rule even when receiving negative feedback

perseveration

repeatedly performing the same action/thought even if it is not achieving the desired goal

the episodic buffer

stores information, thereby providing extra capacity and is connected to LTM, thereby making interchange between WM and LTM possibel

• represents way of increasing storage capacity and communicating with LTM

• expands of Baddeley’s WM model

Peterson & Peterson’s (1959)

• subjects remembered about 80% of three-letter groups if they began recall after counting for just 3s

• only recalled 12% after counting for 18s

• decay

decay

memory trace vanishes after passage of time

the effect of damage to the PFC

if the prefrontal cortex is removed, performance drops to chance

• PFC is important for holding information for brief periods of time

  • Monkey study

WM and the Brain

Working memory does not live in a single spot; it relies on a distributed network of connected regions, centered primarily in the prefrontal cortex

Harrison & Tong (2009)

• brain activity measured with fMRI and they were able to predict with 75-100% accuracy which of the two orientations subjects were looking at

• information about the orientation subjects are remembering is being held in the visual cortex during the delay, so visual cortex is involved in WM

Vogel et al. 2005

neural measures reveal individual differences in controlling access to working memory

High = higher WMC

Low = worse WMC

long-term memory

system that is responsible for storing info for long periods of time

• detail of specific memories fade with time and as other experiences accumulate

serial position curve

memory is better for words at the beginning of a list and at the end of a list than for words in the middle

• primacy effect

  • recency effect

primacy effect

better memory for stimuli present4ed at the beginning of a sequence

recency effect

better memory for stimuli presented at the end of a sequence

Marshall & Werder (1972)

primacy effect; divided subjects into different groups, focusing on the INC group: when seeing a list of words, they were told to code the words by determining a numerical value of the word using a simple scheme

• A= 1, E = 2, I = 3

• Eliminated primacy effect, intact recency effect

• Conclusion: better memory at the beginning is due to longer rehearsal

Glanzer & Cunitz (1966)

recency effect; most recently presented words are still in STM and easy to recall

• had subjects recall words after they counted backward for 30s right after hearing the last world of the list- allowed time for info to be lost from STM

  • Eliminated recency effect

coding

form in which stimuli are represented

visual coding in STM and LTM

recalling visual patterns in the mind

ex. recalling the face of your fourth grade teacher

auditory coding in STM & LTM

STM: misidentifying target letters as another letter that sounds like the target

LTM: playing a song in your head and “hearing” the next song before it comes on

semantic coding in STM

Sachs 1967

• Ss listened to tape recording of a passage and measured

  recognition memory to determine whether they remembered exact

  wording or general meaning

  • Remember general meaning, not exact wording

comparing coding in short-term and long-term memory

• Auditory encoding is predominant in STM (think phone numbers)

• Semantic encoding is predominant in LTM

Henry Molaison (H.M.)

underwent procedure to eliminate epileptic seizures by

removing bilateral hippocampi (1953)

• No longer able to form new LTM, STM intact, eliminated seizures

Clive Wearing

musician who contracted viral encephalitis, which destroyed parts of

medial temporal lobe

• Forgets everything after 1-2 mins, no LTM

• Can still play the piano

K.F.

had damage to parietal lobe after motorbike accident and had

no STM but intact LTM

• Could form and hold new memories in life

Atkinson & Shiffrin (1968) Multi-Store Memory Model

Environment Input → Sensory Memory → Short Term Memory → Long-term Memory

• Attention above arrow between sensory and STM

• Consolidation above arrow between STM and LTM

• Retrieval below arrow between STM and LTM

is the hippocampus also associated with STM?

hippocampus is involved in maintaining novel info

in memory during short delays, so hippo may also play a role in STM

• LTM and STM not as separate as

we once thought

episodic memory

memory for experiences

semantic memory

memory for facts

Tulving (1985)

first to propose that episodic and semantic memories handled different types of info, which can be distinguished based on type of experience associated with each

mental time travel

experience of traveling back in time to reconnect

with events that happened in the past; episodic (remember

semantic memory involves…?

accessing knowledge about the world, not necessarily tied to personal experience—facts, #s, concepts; “knowing”

K.C.

had motorbike accident and suffered damage to hippo and

surrounding structures—lost episodic memory, cannot relive past events

• Knows his brother died 2 yrs ago, but nothing personal

• Remembers facts like where eating utensils are located in kitchen and

bowling terminology

L.P.

suffered from encephalitis, had trouble shopping because she couldn’t remember meaning of words on the shopping list or where things were in the store

• No semantic memory, intact episodic

Levine et al. (2004)

had Ss keep diaries on audiotape describing 1) everyday personal events and 2) facts drawn from semantic knowledge

• Showed major separation but also some

overlap between episodic and semantic

memories

knowledge…?

affects experience

• semantic memory guides experience and influences episodic memories that follow

  • ex. baseball

autobiographical memory

memory for specific experiences of out life, contains both semantic and episodic components

personal semantic memories

facts associated with personal experiences

Westmacott & Moskovitch (2003)

showed that subjects knowledge of public figures can include semantic and episodic components

• ex. remembering who Oprah is, but also where you were when you watched her show

recall is better for…?

names of people who had higher autobiographical significance

• more likely to remember the name of a singer (semantic) if you attended one of their concerts (episodic)

• doesn’t occur when one’s episodic memory is impaired: episodic memory also enhances semantic

forgetting

not always all-or-nothing

• can be expressed as familiarity or recollection

familiarity

semantic, not associated with the circumstances under which knowledge was aquired

• ex. that person looks familiar: who are they and how do I know them?

recollection

episodic, includes details about what was happening when the knowledge was acquired and awareness of the event as it was experienced in the past

• ex. i know that person: that’s Joe from Cog psych

remember/know procedure

subjects are asked if stimulus is familiar and also remember the circumstances under which they originally encountered it or know if the stimulus seems familiar but they don’t remember experiencing it earlier, or they don’t know if they remember seeing the stimulus at all

• remember response = episodic

  • know = semantic

complete forgetting…?

increased over time (don’t know) and remember responses decreased much more than know responses

• memories for 40-50 yr-old events had lost much of their episodic character s

semanticization of remote memories

loss of episodic detail for memories of long-ago events, or as short as 1 week

D.B.

could not imagine future events that would happen to him personally, but could imagine other future events like what might happen in politics or other current events

constructive episodic simulation hypothesis

episodic memories are extracted and recombined to construct simulations of future events

• both episodic and semantic memory systems need to be functioning to think about personal future

explicit memory

conscious, memories we are aware of; declarative memory

• episodic & semantic

implicit memory

unconscious learning from experience is not accompanied by conscious remembering; non-declarative memory

• procedural memory, priming, conditioning

procedural memory

memory for doing things that usually involve learned skills, like riding a bike

ex. Clive Wearing, K.C., and H.M could still perform procedural tasks, just can’t remember learning them

priming

presentation of one stimulus (priming stimulus) changes the way a person responds to another stimulus (test stimulus)

Graft et al. 1985

• subjects read 10-word list and rate liking 1-5

• then tested explicit recall and implicit memory by world completions

  • Amnesiac subjects recalled fewest words

  • Implicit memory similar across groups: priming (they can’t remember seeing the word list consciously)

Perfect & Askew (1994)

subjects scanned magazine articles with ads, but subjects weren’t told to pay attention to the ads

• when asked later to rate ads, gave higher ratings to ones they had been exposed to but only recognized 2.8 ads out of 25 shown

  • mere exposure effect

propaganda effect/illusory truth effect

subjects are more likely to rate statements they have read or heard before as being true, simply because they have been exposed to them before

• even when told the statement is false

classical conditioning

occurs when a neutral stimulus that initially does not result in a response and a conditioning stimulus that does result in a response

ex. presenting a tone followed by a puff of air to the eye that makes a rabbit blink eventually causes the tone to make the rabbit blink

encoding

process of acquiring info and transferring it into LTM

maintenance rehearsal

shallow encoding involving repetition of info to be remembered

• results in worse memory

elaborative rehearsal

deep encoding, involves making meaningful connections with to be remembered info to other info

• results in better memory

Craik & Lockhart (1972)

proposed levels of processing in which memory depends on the depth of the processing an item receives

• shallow vs. deep

forming visual images…?

paired-associate learning/recall

• subjects who created images recalled twice as many words

self-reference effect

memory is better if you asked to relate a word to yourself

• more likely to remember words connected to oneself

  • age differences cross-culturally

generation effect

generating material yourself, rather than passively receiving it, enhances learning and retention

• Slameka & Graf (1978)

Slameka & Graf (1978)

had subjects list word pairs in two ways

• read group: read these paired related worlds

• generate group: fill in the blank with a word that is related to the first word

  • subjects who generated the second word recalled 28% more word pairs

Bower et. al (1969)

subjects studied four separate trees for different categories, then recall

• organized vs. disorganized group

• organized group had better recall that disorganized group

  • retrieval cue

retrieval cue

stimulus that helps a person remember information stored in memory

Roediger & Karpicke

After a 5-minute delay, students who repeatedly studied material performed better (83% recalled) than those who practiced retrieval (71% recalled). However, after a 1-week delay, active testing reversed this: students who did repeated retrieval remembered roughly 61% of the material compared to 40% for those who only restudied

• idea of retrieval practice

consolidation

process that transforms new memories from a fragile state, in which they can be disrupted, to a more permanent state, in which they are resistant to disruption

synaptic consoldiation

involves structural changes at synapses, takes minutes or hours

systems consolidation

gradual reorganization of neural circuits within the brain, takes place over months or even years

• both types occur together, but at different speeds and levels of the nervous system

Hebb (1948)

proposed that learning and memory are represented in the brain by psychological changes that take place at the synapse

never impulses…?

travel down the axon of neuron A, reach the synapse, and neurotransmitter is released onto neuron B

repeated activity can…?

strengthen the synapse by causing structural changes, greater transmitter release, and increased firing- occurs in many surrounding synapses

• LTP

long-term potentiation (LTP)

enhanced firing of neurons after repeated stimulation