Visuospatial memory and learning in first-episode schizophreniform psychosis and established schizophrenia: a functional correlate of hippocampal pathology?
BACKGROUND
Despite a number of studies that have indicated impaired memory function in patients with schizophrenia, there have been few that have used a sensitive measure of right medial temporal lobe pathology. Given the reported findings of reduced hippocampal volume in schizophrenia, we used a theoretically sensitive test of the right medial temporal lobe to determine the nature of the visuospatial memory deficit in the disorder.


METHODS
Seventy-six patients (37 with a first-episode schizophreniform psychosis, and 39 with established schizophrenia) were compared with 41 comparison subjects on a number of tests of visuospatial memory. These included spatial working memory, spatial and pattern recognition memory and a pattern-location associative learning test.


RESULTS
Both patient groups displayed recognition memory deficits when compared to the comparison group. However, only those patients with established schizophrenia (of 9 years duration on average) were impaired on the associative learning test.


CONCLUSIONS
The results indicate either a progressive decline in visuospatial associative learning ability over the course of the disorder, or that poor visuospatial associative learning is a marker for poor prognosis. In addition, these results have implications for our understanding of the role of the right medial temporal lobe in the pathophysiology of schizophrenia.
Wood
S J
SJ
Cognitive Neuropsychiatry Research and Academic Unit, University of Melbourne, Sunshine Hospital, St. Albans, Victoria, Australia.
Proffitt
T
T
Mahony
K
K
Smith
D J
DJ
Buchanan
J A
JA
Brewer
W
W
Stuart
G W
GW
Velakoulis
D
D
McGorry
P D
PD
Pantelis
C
C
D000293:Adolescent; D000328:Adult; D001245:Association Learning / Q000502:physiology; D002908:Chronic Disease; D005260:Female; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D009949:Orientation / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011618:Psychotic Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013702:Temporal Lobe / Q000503:physiopathology*