Memory

Definition of memory

the means by which the mind stores and retrieves information and events experienced.

two main models of memory?

-multi store model

-working memory model

how does the multi-store model explain memory?

the model explains how information flows through a series of storage systems, with three permanent structures in memory.

what are the three main structures in the multi-store model?

-sensory register SR

-short term memory STM

-long term memory LTM

what are the three key features of these main structures that each differ with?

-coding

-capacity

-duration

definition of coding

the means by which information is represented in memory

definition of capacity

the amount of information that can be stored at a given time

definition of duration

the length of time information remains within storage

Describe the SR

-not under cognitive control, but is an automatic response to the reception of sensory information by the sense organs

-first storage system within the MSM

Describe coding in the SR

-info is stored in a raw unprocessed form with sensory stores for different sensory inputs

-info paid attention to passes on to the STM, while the remainder fades quickly through trace decay

what are the separate sensory stores in the SR

echoic store- auditory info

iconic store- visual info

haptic store- tactile info

gustatory store- taste info

olfactory store- smell info

research which supports the idea of sensory information being coded into different sensory stores?

Crowder (1993)

What did Crowder find?

that the SR only retains info in the iconic store for a few milliseconds, but for two to three seconds within the echoic store

-also suggests the stores have different durations

Capacity of the SR?

The capacity of each sensory memory store is very large with the information contained being in an unprocessed, highly detailed and ever changing format.

Research supporting the capacity of the SR?

Sperling 1960

Sperlings proceadure?

-participants were briefly shown a screen with three rows of letters

-they were asked to recall the letters in a specific row by sounding a specific tone which corresponded to a specific row

-recall of letters in the indicated row was high, indicating the capacity of the SR is large (especially the iconic store)

Duration of the SR?

limited duration. different information decays at different rates and this can decrease with age

Walsh & Thompson find?

that the iconic sensory store has an average duration of 500 milliseconds, which decreases as an individual gets older

Describe the STM

-temporarily stores info from the SR

-it is an active(changing) memory system as it contains information currently being thought about

Why does the STM code information

-info that arrives from the SR is in its original raw form(sound,vision) and is encoded so its in a form the STM can more easily deal with

How does the STM code info?

mainly acoustically

but also visually and semantically

Capacity of STM? how can it be increased?

between 5 and 9 items on average

by chunking- where the size of the units of information in storage is increased by giving them a collective meaning

Duration of STM?

between 18-30 seconds on average

Coding of LTM?

mainly semantic-meaning- (also visual and acoustic-Baddeley)

coding of information will be stronger (and thus memories more retrievable) the deeper the level of processing a stimulus that occurs while it is being experienced.

Capacity of LTM?

Unlimited

Information may be lost to due to decay and interference, but not due to capacity

Duration of LTM

up to a whole life time

info in LTM doesn't have to be continually rehearsed to be retained

What did Peterson and Peterson 1959 investigate?

Duration of STM

Proceadure of Peterson and Peterson

-they read nonsense trigrams (words of three letters that don't form recognisable words) to participants

-they got them to count backwards in threes from a large three-digit number for varying periods of time

What did Peterson and Peterson find?

90% of trigrams were recalled correctly after 3 seconds but only 5% after 18 seconds

-duration of STM is 18 to 30 seconds

Limitations of P and P work?

-different trigrams were used on each trial, this may have led to interference between items, leading to decreased recall

-recalling nonsense trigrams has little relevance to STM tasks in everyday life and therefore lacks mundane realism.

Bahricks research and findings?

-showing high school year books to pps who graduated 18 years ago w 90% being able to match names to faces. Then those who graduated 47 years ago- 60%.

Capacity research?

Jacobs/Miller - people are able to remember 7 letters or 9 words

Aim and method of Baddeley's research?

Aim: Investigated how information is encoded in short-term memory (STM) and long-term memory (LTM).

Method:Participants were presented with lists of words.Four types of word lists: acoustically similar (e.g., cat, cab, can), acoustically dissimilar, semantically similar (e.g., big, large, huge), and semantically dissimilar.Recall was tested immediately (for STM) and after a delay (for LTM).

Baddeley's findings?

STM: Participants struggled with acoustically similar words, suggesting STM relies on acoustic encoding.

LTM: Participants struggled with semantically similar words, suggesting LTM relies on semantic encoding.

Strengths of MSM?

-research supports concept of multiple memory stores

-HM case study- lost long term memory due to labotomy, short term memory intact

Limitations of MSM?

-oversimplified

-multiple LTM and STM stores

-role of rehearsal questioned

-machine reductionist

Who designed the working memory model to replace the idea of a unitary STM from the original multi store model?

Baddeley and Hitch 1974

What are the key stores in the WMM?

Central executive

Phonological loop

Visuo-spatial sketchpad

Episodic buffer

Definition of the central executive?

directs attention, monitors incoming information and allocates tasks to subsystems.

Definition of the phonological loop?

is a subsystem process for auditory information and preserves the chronological order of information.

Definition of visuospatial sketchpad?

is a subsystem process for visual and spatial information

Definition of the episodic buffer?

is a temporary storage of information to integrate visual, spatial and auditory information in other stores.

What are the key features of the CE

-acts like the boss of the WMM

-controls and organizes information coming in from the senses

-helps with problem solving, decision-making, and reasoning

-directs attention and sends information to the three other parts of the system

-doesn't store information itself

-has limited capacity-can only handle one thing at a time

What are the two parts of the PL

-phonological store(inner ear)- briefly holds sounds you've just heard.

-articulatory process(inner voice)- repeats words in your head to keep them in memory(maintenance rehearsal)

Who split the PL into two parts?

Baddeley 1986

Key features of the PL

-deals with sound and speech info

-keeps info in the order it was heard

-has a small capacity-holds info for about two seconds

two parts of visuospatial sketchpad

-visuo-cache(store)- passively stores shapes and colours

-inner scribe(spatial relation)- actively stores object positions and movement in 3D space

Key features of the Episodic Buffer

-added by Baddeley in 2000 to fix a gap in the model

-acts as a temporary store that connects information from different sources

-give the CR extra storage but only holds about four chunks of info

-links to all parts of working memory and LTN

-combines visual,spatial and auditory information while keeping the order of events

-can pull info from LTM to help working memory when needed

A strength of the WMM

-less emphasis on rehearsal than the MSM. rather than being the key process, rehearsal is just one possible process in the WMM.

-this can therefore help to explain why in real life some things end up in our long term memory even though we haven't rehearsed them-suggests other processes are at work

A lab study that supports the model?

Gathercole and Baddeley 1993

Gathercole and Baddeley 1993 method

one group of participants had to complete two tasks using the visuo-spatial sketchpad at the same time

another group had to do two tasks at the same time but one was using the vss and another was with the pl

Gathercole and Baddeley 1993 findings

found that performance was much better in the participants doing tasks which used separate systems

Weakness of the CE in the WMM

-idea of CE is simplistic and vague, model doesn't explain exactly what the CE is apart from being involved in attention.C-but it is difficult to design tasks to test the central executive

Weakness of the LTM in the WMM

only explains how information is dealt with in the short term memory- doesn't explain how info is transferred to long term memory

Weakness of the research of WMM

research which has supported the wmm has been laboratory studies. reduces the ecological validity of the evidence as highly controlled studies may not be representative of what happens in the real world

Forgetting

the failure to retrieve memories

Retrieval failure

An explanation for forgetting when material is stored in the LTM but cannot be consciously recalled as a result of a lack of retrieval cues to 'jog the memory'.

Interference Theory IT

An explanation for forgetting when similar material is confused in recall from the LTM

Proactive interference

a form of interference that occurs when past memories inhibit an individual's full potential to retain new memories

Retroactive interference

a form of interference that occurs when newly learned information interferes with the recall of previously learned information

Schmidt et al. 2000

the findings suggest that learning new patterns of street names when moving house makes an recalling an older pattern of street names harder to do.

retroactive interference does seem to be able to explain forgetting in some real life situation

research that supports interference theory rather than trace decay thoery?

Baddeley and Hitch 1977- found that forgetting was due more to the number of games played, rather than time passed

cue-dependent fogetting CDF

a type forgetting, based on a failure to retrieve the prompts that trigger recall. info is still in the LTM but can't be accessed

How did Tulving 1973 explain CDF

as the encoding specificity principle- where recall is hindered if the context of recall is different to that at coding

two main forms of CDF?

-context-dependent failure

-state-dependent failure

context-dependent failure

a form of CDF where recall occurs in a different external setting to coding

state-dependent failure

a form of CDF where recall occurs in a different internal setting to coding

study supporting context-dependent failure

Godden and Baddeley 1975

got divers to learn material either on dry land or while underwater.

recall was found to be worse when it occurred in a different context to coding than in the same context.

study supporting state-dependent failure

Overton 1972

got participants to learn material when either drunk or sober and found that recall was worse when participangts were in a different internal state at recall than their internal state at coding

weakness of CDF

many studies supporting cdf are lab based and not like everyday memory tasks

weakness of Godden and Baddeleys findings- that CDF can't explain all forms of forgetting

they only occurred when the divers had to free recall items learned. when given a recognition test(saying whether a named item was in the list or not), the context-based effect wasn't seen

strength of CDF

many psychologists see CDf as the main reason for forgetting in LTM , due to the amount of research evidence supporting the importance of cues and how they trigger memory

repression

the placing of traumatic memories into the unconscious mind in order to reduce the anxiety they can produce

Eyewitness testimony EWT

evidence provided by those recalling an event who were present when the event took place

What did Bartlett state 1932

that memories aren't accurate snapshots of events but are reconstructions of events, influenced by active schemas (ready-made expectations based on previous experiences, moods and existing knowledge)

What did Bartlett find in 1932?

when western cultural participants were told an Indian story "the war of the ghosts", their memory became distorted and they changed details of the story to make it fit into a western cultural viewpoint.

illustrates how memory can be affected by cultural schemas

factors affecting the accuracy of the EWT?

Misleading information (leading questions and post-event discussion) and anxiety

misleading information

information that suggests a desired response

leading questions

questions that prompt or encourage required responses

-increase the likelihood that an individuals schema will influence them to give a desired answer

post-event discussion

Information added to a memory after the event has occurred

-false memories can be stimulated by misleading post-event experiences