Two Key Studies on Models of Memory: Glanzer & Cunitz (1966) & Baddeley et al. (1973) (HL IB Psychology)

Key Study: The MSM - Glanzer & Cunitz (1966)

Aim: To investigate serial position effect as evidence for there being two separate stores of memory (STM and LTM) which supports the Multi-Store Model of Memory

Participants: 46 males who were all enlisted in the US army

Procedure: Each participant was individually shown 15 lists each containing 15 words. There were three conditions of the independent variable:

• Immediate recall after being shown the list

• Recall after a 10-second interference task (the Brown-Peterson technique of counting backwards aloud from a given number in threes)

• Recall after a 30-second interference task (the Brown-Peterson technique of counting backwards aloud from a given number in threes)

Results: 

• Participants in the immediate recall condition showed the expected ‘U’ curve of the serial position effect - i.e. more items recalled from the beginning and the end of the list, showing both primacy and recency effect

• Participants in the 10-second delay condition showed a similar primacy effect to the immediate recall group but much less of a recency effect

• In the 30-second delay condition the primacy effect was high but the recency effect had disappeared with fewest items recalled from the end of the list compared to the other two conditions.

Conclusion: By preventing rehearsal with a 30-second interference task, items from the end of the list had not been rehearsed in STM so they could not be transferred to LTM and so the recency effect is prevented. In other words, there appear to be two separate storage facilities for STM and LTM.

Evaluation of Glanzer & Cunitz (1966)

Strengths

• This is a well-controlled lab experiment with standardised procedure which makes it replicable thus high in reliability

• The dependent variable was measured quantitatively which means that the results are easy to compare and to analyse statistically

Limitations

• The procedure lacks ecological validity due to the artificial nature of the task

• The use of an independent measures design could give rise to participant variables i.e. one condition of the IV could have consisted of people whose memory was naturally better than in the other groups

Key terms:

• Serial position effect

• Primacy effect

• Recency effect

Key Study: The WMM - Baddeley et al. (1973)

Aim: To investigate the existence of the VSS and the PL as separate components in the Working Memory Model by using a dual-task activity (dual-task study)

Participants: There is no information available as to who was included in the sample

Procedure: A dual-task lab experiment in which participants were given a tracking task (following a spot of light with a pointer around a circular path) while imagining block capitals in their head such as H, T, F and E

• Condition A: Participants were asked to start at the bottom left-hand corner of the path and to begin tracking the shape with their light-pointer. They were asked to respond verbally to each angle with a ‘yes’ if it included the bottom or top line of the letter and a ‘no’ if it did not. So, if the participant was thinking of a letter ‘F’ then they would respond that yes, it had a top and a middle line but no bottom line. They did this while tracking the spot of light

• Condition B: The participants started tracking the pattern with the light-pointer and they were then told to imagine one of the letters, ‘F’ for example. While they were tracking the pattern they were asked, ‘Does this letter have a top line/middle line/bottom line in it’? But they were asked to just imagine the letter in their head. So, they were having to follow a pattern while at the same time imagine a letter in their head

Results: Participants in condition B experienced great difficulty in tracking the spot of light and at the same time accurately identifying in their head whether the letter had a top/middle/bottom line. Tracking and letter imagery tasks were competing for the limited resources of the Visuo-Spatial Sketchpad, whereas the tracking and verbal tasks in condition 1 (responding verbally whilst visualising the letter) used separate components: the VSS and Phonological Loop

Conclusion: There may be separate slave systems – the VSS and the PL - which operate in working memory. Overloading one of the slave systems with two tasks means that it cannot function properly

Evaluation of Baddeley et al. (1973)

Strengths

• The slave systems (PL and VSS) were clearly operationalised in this study which increases the reliability of the findings

• This was one of the first pieces of research to demonstrate the dynamic nature of STM, seeing it as a system of 'moving parts' rather than a simple unitary store

Limitations

• It is difficult to know whether the participants in condition B were actually imagining the letters or thinking about something else which lowers validity to some extent

• This was an artificial task which means that the study lacks mundane realism

Key terms:

• Dual-task

• Visuospatial Sketchpad

• Phonological loop