Centre for Clinical Research in Neuropsychiatry, Mt Claremont, WA 6010, Perth, Australia.
Psychiatry Res. 2010 Oct 30;179(3):253-8. doi: 10.1016/j.psychres.2009.09.002. Epub 2010 May 21.
Spatial working memory (SWM) dysfunction is a central finding in schizophrenia; however, more evidence of impaired maintenance over time is required. Consequently, the present study examined SWM maintenance over short unfilled delays, and with encoding equated. The influence of a vertical reference frame to support maintenance was also investigated. The performance of 58 patients with schizophrenia and 50 healthy controls was assessed using the Visuo-Spatial Working Memory (VSWM) Test across three unfilled delays (0, 2, and 4s). Inaccuracy of direction and distance responses was examined at each delay duration. The results showed that performance was significantly less accurate for both distance and direction responses at 2 and 4s delays in schizophrenia, but was not significantly different from controls at the 0s delay. Patients showed a particularly marked loss of accuracy between the time interval of 0-2s. Furthermore, schizophrenia participants exhibited significantly greater response variability at the vertical axis of symmetry than controls at the 2 and 4s delays, but not at the 0s delay. These data clearly show both impaired maintenance over time and difficulty using a vertical frame of reference in schizophrenia. The latter findings may reflect, in part, dysfunctional reference-related inhibition.
空间工作记忆（SWM）功能障碍是精神分裂症的一个核心发现；然而，需要更多证据表明随着时间的推移维持能力受损。因此，本研究在编码相等的情况下，考察了短时间无填充延迟下的 SWM 维持情况。还研究了垂直参考框架对维持的支持作用。使用视觉空间工作记忆（VSWM）测试，对 58 名精神分裂症患者和 50 名健康对照者在三个无填充延迟（0、2 和 4 秒）下进行了评估。在每个延迟持续时间内检查了方向和距离响应的准确性。结果表明，在 2 秒和 4 秒延迟时，精神分裂症患者的距离和方向响应的准确性明显降低，但在 0 秒延迟时与对照组没有显著差异。患者在 0-2 秒的时间间隔内表现出明显更大的准确性损失。此外，与对照组相比，精神分裂症患者在 2 秒和 4 秒延迟时，在垂直对称轴上的反应变异性显著增加，但在 0 秒延迟时则没有。这些数据清楚地表明，精神分裂症患者的时间维持能力受损，并且难以使用垂直参考框架。后一种发现可能部分反映了参考相关抑制的功能障碍。
