Coding
How information is modified and stored in the brain.
(Visual, semantic and acoustic)
Duration
Length of time you can store information.
Capacity
How much information you can store.
Capacity in the LTM and the STM
LTM - unlimited
STM - 7 +/- 2 items
A01 - capacity - Jacobs (1887)
Measured digit span
9.3 average numbers remembered
7.3 average letters remembered
Evidence for limited capacity of STM ( 7 +/- 2 items)
A01 - Capacity - Miller (1956)
7 +/- 2 items
Recall 7 dots, letters, musical notes
Chunking
A01 - coding - Baddeley (1966)
To test STM participants recall words immediately
To test LTM participants recall words 20 minutes later
Acoustically similar words: immediately: difficult later: easy
Semantically similar: immediately: easy later: difficult
Information is coded acoustically in the STM and semantically in the LTM.
A03 - coding - Brandimote et al (1992)
Limitation - encoding of the STM - contradictory evidence
Brandimore et al (1992) - visual encoding in the STM prior to recall. Nelson and Rothbart (1972) acoustic coding in the LTM.
Encoding in STM is not exclusively acoustic. Encoding in the LTM is not exclusively semantic.
Limits generalisability.
A03 - coding - strength
Strength of Badeley study - evidence for distinct and separate memory stores in STM and LTM.
Different encodings.
Developed MSM of memory.
Reliable findings.
A03 - coding - weakness
Baddeley study lacks ecological validity - lab setting.
Meaningless words.
Memory has more personal significance in the real world.
Lacks ecological validity.
A01 - duration - Peterson and Peterson (1959) - STM
Aim: investigate the duration of the STM
Participants: 24 university students
Procedure: 8 trials. Participants were given a consonant trigram and a three-digit number.
3 seconds - 80% recall
9 seconds - 20% recall
18 seconds - less than 10% recall
Duration of STM is less than 18 seconds.
A01 - duration - Bahrick et al (1975) - LTM
aim: investigate the duration of the LTM
participants: 392 US aged 17-74
procedure: tested photo recognition and free name recall from the participants high school yearbook.
photo recognition: recall 50 names
free recall: asked to list names they can remember
findings (photo recognition): 15 years - 90% 48 years - 70%
findings ( free recall): 15 years - 60% 48 years - 30%
Duration of LTM can last a very long time
A03 - duration - STM - P and P
In Peterson and Peterson (1959) study participant were asked to count backwards in 3s or 4s as a distraction task which may have overwritten the trigrams in memory, leading to displacement rather than preventing rehearsal.
A03 - duration - strength - LTM
Strength of Bickmans results - higher ecological validity than Peterson and Peterson.
Memory was tested on real life - high mundane realism.
Can be generalised to real-world settings.
High ecological validity.
