Zusammenfassung der Ressource
Schmolck et al. (2002)
- ABOUT
- AIM
- To find out if Semantic LTM is linked to a particular part of the brain
- IV
- The extent of brain injury
- DV
- Scores on 9 separate tests of semantic LTM
- SAMPLE
- 6 patients with severe damage to the MTL and 8 Controls
with no brain damage
- 3 of the patients also had damage to the temporal cortex
generally (MTL+)
- METHODS
- A natural experiment with matched pairs design.
- The type of cognitive test is a repeated measures design because each
participant did every test.
- PROCEDURE
- Schmolck created 9 tests for Semantic LTM functions. All were
based on a set of 48 drawings
- Half of animals and half of objects
- These pictures were grouped in sixes:
6 land animals, 6 birds, 6 musical
instruments, 6 vehicles, etc.
- EXAMPLES OF THE 9 TESTS
- Category sorting: the participants were given all 48 pictures and
asked to sort them into “living” or “man made”
- Category fluency: the participants were asked to give as many examples as possible from each
theme within a minute
- The participants were tape recorded and their
responses transcribed (typed up).
- 14 'raters' checked each transcript for reliability
- They ooked for grammar/syntax errors in the way the participants
spoke because problems with language also indicates trouble with
semantic memory.
- RESULTS
- MTL+ Group: These patients did significantly worse in all the tests
- There was a positive correlation between the
amount of brain damage and the number of
mistakes.
- H.M. did better than the MTL+ patients but slightly worse than the other
MTL patients who had damage solely to the hippocampus
- CONCLUSION
- A clear link between damage to the
temporal cortex generally and the loss of
semantic LTM.
- Patients with damage specific to the hippocampus suffered loss of
episodic memory, but not semantic memory.
- This suggests that semantic and episodic LTM are encoded in
different parts of the brain,
- EVALUATION
- GENERALISABILITY
- Only a small sample was used which
means results can easily be distorted by
anomalies
- RELIABILITY
- It has standardised procedures that could be replicated by other researchers.
- 14 raters to check the participants’ scores and their agreement gives this study
inter-rater reliability.
- APPLICATION
- Helps us understand the side-effects of brain damage on memory
- VALIDITY
- Lacks ecological validity
as tasks are artificial
- ETHICS
- This study involved patients who could not give valid
consent, because they would not be able to remember
having the study explained to them.