Models of memory

Psychologists often create models in order to try to understand how memory works. One such model is the multi-store model proposed by Atkinson & Shiffrin (1968). Another model is the Working memory model proposed by Baddeley & Hitch (1974).

The Multistore Model of Memory

Key assumptions of the multi-store model:

• The model is a linear model and describes how information flows through the memory system.

• The model suggests that memory is made up of three separate stores linked by processing.

• The model describes the sensory register (SR), short-term memory (STM) and long-term memory (LTM).

• Each store has its own characteristics in terms of coding, capacity and duration.

How does the multi-store model work?

• Information gathered by the sensory organs enters the sensory register.

• Only the small amount paid attention to passes to short-term memory for further processing, the rest of the information is lost very quickly.

• Information in short-term memory that is actively processed enough (mainly through rehearsal), transfers to long-term memory.

Sensory Register

This part of the memory system receives and stores information from the environment through our senses.

Coding in the sensory register:

• Sensory memory is modality specific which means that information is stored in the form it arrives in and each five senses have their own memory store. For example, visual information enters the iconic store and sound information enters the echoic store. Research to support is Crowder (1993)

Capacity of the sensory register:

• The capacity of the sensory register is quite large.

• Research to support: Sperling (1960) - flashed a 3×4 grid of letters onto a screen for one-twentieth of a second, and asked participants to recall the letters of one row.

Duration of the sensory register:

• All sensory memory stores have limited duration (about 0.5 - 3 seconds)

• Research to support: Walsh & Thompson (1978) - found that the iconic sensory store has an average duration of 0.5 seconds, which decreases as individuals get older.

Short Term Memory

STM temporarily stores information received from the SR.

Coding in STM:

• Short term memory tends to encode information acoustically.

Capacity of STM:

• STM has a limited capacity, as only a small amount of information is held in the store.

• Between 5-9 (otherwise known as 7+ or - 2, Miller’s magic number) items can be held, though capacity can be increased by chunking which involves putting items into groups.

• Research to support: Miller (1956) - Participants were read a series of numbers and repeated them back to the researcher in the order they were told. The number of digits they had to recall increased by 1 every round.

Duration of STM:

• The amount of time information remains within the STM without being lost is limited to a maximum of about 30 seconds. This can be extended by rehearsal of the information, which if done long enough will result in the transfer of information into the LTM.