Shallice and Warrington Study (cognitive) Flashcards
1
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Shallice and Warrington Study (cognitive)
Aim
A
2
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Shallice and Warrington Study (cognitive)
Procedure
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- First experiment - had to recall a series of 4 -5 letter words using immediate recall (3 testing sessions)
- Second experiment - had to recall a series of 3 letter words that were delivered verbally, before recalling the words the subject had to count forward in 1’s as fast as possible. Recall was allowed until failure. Trial length varied from 0, 5, 10 or 15 sec
- **Third experiment **- Ten series involving pairs of letters were spoken to the subject. Each letter of the pair was spoken 1 sec apart. The subject given 5 secs to recall each letter of the pair before the next pair was presented
- Fourth experiment - A string of 5 letters were spoken to the subject at a rate of 1 per second. 3 recall conditions: (A. presentation of a probe letter to the subject who had to state whether or not the probe letter was used in the string, B. The subject had to identify the last letter of the string before the probe letter was given, C. Twenty second delay before the probe letter was given) Subject was told before each set which retrieval conditions would be used)
- Fifth Experiment - Subject had to detect which digit set was missing from digit sets of 3m 4 or 5. Digit strings lengths of 2, 3 or 4 were drawn randomly and tested for recall
3
Q
Shallice and Warrington Study (cognitive)
Findings
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- Recency is limited in recall to the 1st serial position instead of the 5th or 6th and primacy is limited to the 1st trial instead of the 3rd and 4th trial
- When the recall involved digit spans the subject was mainly using LTM
- The list length demonstrated a recency recall of effect of 3 figure digits
- The subject’s impairment is not limited to one retrieval method
- Reduction in STM capacity
- STM function is impaired (STM traces are poorly laid down or lose strength quickly) but LTM is functioning is normal
- Inputs to the STM and LTM are parallel instead of serial
- Provides evidence that there are at least two verbal stores, one in the STM and the LTM which operate independently
4
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Shallice and Warrington Study (cognitive)
Limitations
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- External validity: Cannot generalize a single case study
- Validity of method used to determine LTM capacity is questionable therefore difficult to use for comparison
5
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Shallice and Warrington Study (cognitive)
Ethical Considerations
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- Informed consent: Difficult to consent to further research when suffering from memory issues
6
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Shallice and Warrington Study (cognitive)
Research Method
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Case Study
