Can disorganisation of semantic memory account for the abnormalities of thought in schizophrenia-a controlled experimental study.
BACKGROUND
Disorganisation of semantic memory could provide a cognitive explanation for the disturbances of thinking and reasoning in schizophrenia. In this study, we directly test this explanation by identifying patients with disorganised semantic categories and then examine how they use their knowledge about these same categories in an inductive reasoning task.


METHODS
Experiment 1 utilised a semantic category-sorting task to identify patients with disorganisation of semantic memory. In Experiment 2, the patients with disorganised categories carried out a category-based inductive reasoning task. Accurate performance on this task requires access to well-organised semantic knowledge about the objects and categories used in Experiment 1.


RESULTS
Patients with disorganised semantic categories in Experiment 1 did not demonstrate any difficulties or unusual responses when reasoning about the same categories in Experiment 2.


CONCLUSIONS
Disorganisation of semantic memory may not be the primary cause of disturbed reasoning or thought in schizophrenia. Patients with schizophrenia tend to generate ad hoc categories, which are unsuited to the current context. Impaired performance on semantic memory tasks can arise from a misunderstanding of social context.
Department of Psychology, University of Hertfordshire, Hertfordshire, AL10 9AB, UK.
N E A
NE
Green
D J
DJ
Done
S H
SH
Anthony
P J
PJ
McKenna
M
M
Ochocki
D000328:Adult; D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000453:epidemiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011340:Problem Solving; D011582:Psychological Theory; D012559:Schizophrenia / Q000150:complications*; D012660:Semantics; D012720:Severity of Illness Index; D013850:Thinking