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.
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.
Authors: Joachim Klosterkötter; Stephan Ruhrmann; Frauke Schultze-Lutter; Raimo K R Salokangas; Don Linszen; Max Birchwood; Georg Juckel; Anthony Morrison; José Luis Vázquèz-Barquero; Martin Hambrecht; Heinrich VON Reventlow Journal: World Psychiatry Date: 2005-10 Impact factor: 49.548
Authors: Michael J Coleman; Olga Krastoshevsky; Xiawei Tu; Nancy R Mendell; Deborah L Levy Journal: Schizophr Res Date: 2012-05-27 Impact factor: 4.939
Authors: Alice M Saperstein; Rebecca L Fuller; Matthew T Avila; Helene Adami; Robert P McMahon; Gunvant K Thaker; James M Gold Journal: Schizophr Bull Date: 2006-05-10 Impact factor: 9.306
Authors: Weidong Li; Yu Zhou; J David Jentsch; Robert A M Brown; Xiaoli Tian; Dan Ehninger; William Hennah; Leena Peltonen; Jouko Lönnqvist; Matti O Huttunen; Jaakko Kaprio; Joshua T Trachtenberg; Alcino J Silva; Tyrone D Cannon Journal: Proc Natl Acad Sci U S A Date: 2007-11-02 Impact factor: 11.205