Models of Memory

Multi-Store Model of memory

• Devised by Atkinson & Shiffrin as a way of understanding where memories are encoded and stored

• A linear representation of the ways in which information is retained and stored in the memory or lost

• The model consists of three separate storage units:

• the sensory memory/register

• short-term memory (STM) 

• long-term memory (LTM)

Sensory register

• The sensory register is the point where environmental stimuli are picked up by sight, sound, smell, touch, or taste

• Sounds are encoded as echoic memory and images are encoded as iconic memory

• This environmental information is held onto for half a second

• Any information in the SR that is noticed or paid attention to is then passed onto STM 

Short term memory

• A temporary storage for holding onto information

• The capacity is 5-9 items 

• The duration is 30 seconds

• New information pushes existing information out due to the limited duration and capacity

• Rehearsal us necessary so that memories pass to LTM

• Maintenance rehearsal: repeat information verbally

• Elaborative rehearsal: Learn information in ways like writing

• Unrehearsed information is lost from STM via displacement

• Encoding happens acoustically i.e. via sound

• STM can be improved by ‘chunking’ information so that it is easier to ‘digest’

Long term memory

• A large storage holding a vast number of memories

• Both the capacity and the duration of LTM is limitless

• Information may decay if it is not visited frequently or if the cues to retrieve it are missing

• There is no evidence that any items from LTM are lost forever 

• Encoding in LTM happens semantically i.e. via meaning

Strengths of MSM

• The first model to conceptualise memory 

• The existence of separate memory stores has been supported by lab experiments 

Weaknesses of MSM

• Doesn’t explain how STM and LTM operate

• Research has identified that there is more than one type of LTM:

• Episodic memory contains information from your own personal history

• Procedural memory contains information that helps you to perform actions such as riding a bike 

• Semantic memory contains information as to meaning e.g. knowledge about the world 

Name of MSM study

Peterson and Peterson

Peterson and Peterson Aim

To investigate the duration of short-term memory and to provide empirical evidence for the multi-store model. 

Peterson and Peterson Procedure

• Lab experiment

• 24 participants who were all psychology students had to recall trigrams 

• The trigrams were presented each one at a time and had to be recalled after intervals of 3, 6, 9, 12, 15 or 18 seconds

• The students were asked to count backwards in threes or fours from a specified random number until they saw a red light appear to prevent rehearsal

• This is known as the Brown Peterson technique

Peterson and Peterson Results

• After 3 seconds, 80% of the trigrams were recalled correctly 

• After 6 seconds it fell to 50% 

• At 18 seconds, less than 10% of the trigrams were recalled correctly

• Found short-term memory has a limited duration when rehearsal is prevented

• The rehearsal being taken away results in decay.

Peterson and Peterson Conclusion

This experiment supports the multi-store model of memory in which short-term memory is different from long-term memory in terms of duration.

Working Model of Memory

• Devised by Baddley and Hitch as a response to MSM

• Focuses on short term memory only

Central executive

• Key component in the model

• Directs attention to tasks

• Allocates information to different systems

• Deals with problem solving

• Limited capacity

Phonological loop

• Deals with auditory information and language, both written and spoken

• Baddeley divided it into phonological store (holds what we heard) and articulatory process (holds words heard / seen and repeats them like a voice)

Visio-spatial sketchpad

• Visual and spatial information stored here

• Visual = what things look like

• Spatial = relationship between things, e.g. directions

• Divided into visual cache (information about form and colour) and inner scribe (spatial and movement information, transfers to central executive)

Episodic buffer

Links information across domains to form units of visual, spatial and verbal information with time sequencing, for example memory of a story or a movie sequence

Name of WMM study

Landry and Bartling

Landry and Bartling Aim

To investigate if articulatory suppression wicked influence recall of a written lust of phonologically dissimilar letters in a serial recall

Landry and Bartling Procedure

• 34 undergraduate psychology students

• The participants viewed one practise list before the experiment started

• There were ten lists each consisting of a series of 7 letters randomly constructed from the letters F,K,L,M,R,X and Q

• These letters were chosen because they didn’t sound similar

• The experimenter presented one letter series at a time

• In the control group, the experimenter showed participants a printed list for 5 seconds, waited 5 seconds, then had to write the correct order of the letters on the answer sheet

• This was repeated 10 times

• In the experimental test, participants had to repeatedly say the numbers ‘1’ and ‘2’ at a rate of 2 numbers per second from the time of presentation of the list until the time they filled the answer sheet

• This was repeated 10 times

• Each trial was scored for accuracy of recall

• The trial was scored as correct if the letters were in the correct position

Landry and Bartling Results

• The scores from the experimental group were much lower than the scores from the control group

• The mean percent of accurate recall in the control group was 76%

• The mean percent of accurate recall in the experimental group was 45%

• The standard deviation was 0.13 for control and 0.14 for experimental

Landry and Bartling Conclusion

Articulatory suppression significantly hinders the phonological loop's ability to rehearse and recall information