Evaluating MSM of memory

• Proved that STM had a capacity of 5-9 items using the digit span technique with immediate serial recall. 
• Read aloud a digit string to pps, starting with 3 numbers, increasing each time up to 11. (Changed the numbers to prevent practice). 
• pps repeated back (verbally) the digit string they just heard in the correct order. 
• Miller found that STM capacity ranged between 5-9 items - supporting the STM capacity. 
• AO2 - Lab exp (all strengths & weaknesses specific to the study)

• Proved that duration of LTM lasted up to a lifetime using the high school year book photographs. 
• (longitudinal) Graduates from a high school over a 50yr period. 
• Split graduates into two groups to test recall duration. 
• Recall group - identified people in photographs 
• Recognition group - matched names to the faces. <—This group were best at recalling names.
• Recog: After 14yrs - 90% accurate - 60% accurate after 47yrs
• Recall: 60% accurate after 7yrs - 20% accurate after 47yrs
• Showing LTM duration is long.

• AO2 - High eco val (real life) 

  AO2 - 47yrs might be an early cut off point to represent a lifetime of memory - doesn’t consider the natural decline of memory with age.

•  Proved that STM duration was no longer than 30 seconds.
•  Quickly showed pps consonant trigrams. 
•  pps were asked to count backwards in 3’s from desired number (prevent rehearsal).
• Pete&Pete asked them to recall trigram after 3,6,9,12,15 and 18 seconds.
• Found that after 3secs recall v good (80% of trigrams remembered). After 18secs fewer than 10% were remembered.
• Therefore STM duration isn’t much longer than 18 secs.

AO2 - Lab exp (all strengths & weaknesses specific to the study)

Had severe brain damage to hippocampus (LTM).

Both lost ability to form new long-term memories.

However STM worked fine.

This provides strong neuropsychological evidence that STM and LTM are different stores in the brain as only LTM was affected.

AO2 - High in eco val, very useful,

AO2 - Ethics

AO2 - sample size of 1 - can’t generalise

•  Activity is shown in hippocampus when LTM tasks are carried out.
• (Explains why damage to hippocampus causes LTM impairment.)
• Activity is shown in prefrontal cortex when STM tasks are carried out.
• Suggesting two different stores - adding validity to MSM.

AO2 - Scientific, objective