Abstract
Background
Spatial working memory impairments are among the neurocognitive deficits that may
mark genetic predisposition toward schizophrenia. We previously reported that impairment
on the spatial span subtask of the Wechsler Adult Intelligence Scale—Revised increased
in a dose-dependent manner with increasing genetic predisposition toward schizophrenia
in a sample of discordant twins; however, it remains to be determined whether these
deficits reflect difficulties with encoding, maintenance, manipulation, time-tagging
of visual spatial information, storage capacity, or complex motor response.
Methods
We developed a spatial delayed response task in which memory set size was parametrically
varied, holding constant manipulation and decision processes. We then reassessed 80
of the previously studied twins (17 probands with 8 monozygotic co-twins and 13 dizygotic
co-twins, and 42 healthy twins).
Results
The spatial delayed response task was sensitive to genetic loading for schizophrenia
but did not provide evidence for capacity limitations in probands or their co-twins.
Conclusions
The findings suggest that deficits in the encoding or storage aspects of short-term
spatial mnemonic processing may be an effective endophenotypic marker for schizophrenia.
Keywords
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References
- Gating and habituation of the startle reflex in schizophrenic patients.Arch Gen Psychiatry. 1992; 49: 206-215
- The inheritance of neuropsychological dysfunction in twins discordant for schizophrenia.Am J Hum Genet. 2000; 67: 369-382
- The genetic epidemiology of schizophrenia in a Finnish twin cohort. A population-based modeling study.Arch Gen Psychiatry. 1998; 55: 67-74
- A coefficient of agreement for nominal scales.Educ Psychol Meas. 1960; 20: 37-46
- Working memory dysfunction in schizophrenia.J Neuropsychiatry Clin Neurosci. 1994; 6: 348-357
- Clinical genetics as clues to the “real” genetics of schizophrenia (a decade of modest gains while playing for time).Schizophrenia Bull. 1987; 13: 23-47
- A turning point in schizophrenia genetics.Neuron. 1997; 19: 967-979
- The genetics of schizophrenia.Schizophrenia Bull. 1993; 19: 261-285
- Schizophrenics show spatial working memory deficits.Arch Gen Psychiatry. 1992; 49: 975-982
- Spatial working memory deficits in the relatives of schizophrenic patients.Arch Gen Psychiatry. 1995; 52: 821-828
- Wechsler Adult Intelligence Scale—Revised (WAIS-R), Manual. Psychological Corp, Cleveland, OH1981
Article info
Publication history
Accepted:
August 22,
2002
Received in revised form:
August 8,
2002
Received:
May 23,
2002
Identification
Copyright
© 2003 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.