Elvevåg B, Duncan J, McKenna P J
MRC Cognition and Brain Sciences Unit and Fulbourn Hospital, Cambridge.
Psychol Med. 2000 Jul;30(4):885-97. doi: 10.1017/s003329179900255x.
Cognitive deficits in schizophrenia have recently been ascribed to impaired representation and use of cognitive context. Context is defined as relevant information held temporarily in mind to mediate appropriate but often non-habitual responses.
Parallel studies in a variety of cognitive domains were designed in order to explore the generality of any schizophrenic deficit in context use. In all of the tasks (a Stroop task, a Continuous Performance Task and a cued spatial location task), we examined how performance was affected by the time for which contextual information must be held in mind, and by whether context or task demands were consistent or varying between trials. It was predicted that manipulation of these variables would produce tests especially sensitive to schizophrenic attentional problems.
Predictions were partially confirmed. Although increasing contextual demands failed in most cases to produce disproportionate slowing of performance in patients, error data were largely in line with predictions. At the same time, the data did not suggest a simple unitary context deficit. Instead, different aspects of context--the time over which contextual information must be held in mind and the consistency of context--were differentially important in different tasks.
The cognitive impairments of schizophrenic patients cannot be simply characterized as a generalized context deficit. A more differentiated, if not task specific, picture of schizophrenic deficits is suggested.
精神分裂症的认知缺陷最近被归因于认知情境的表征和运用受损。情境被定义为临时保存在脑海中以介导适当但通常非习惯性反应的相关信息。
设计了在各种认知领域的平行研究,以探索精神分裂症患者在情境运用方面任何缺陷的普遍性。在所有任务(一项斯特鲁普任务、一项连续操作任务和一项线索空间定位任务)中,我们研究了情境信息必须在脑海中保持的时间以及情境或任务要求在试验之间是一致还是变化如何影响表现。预计对这些变量的操纵将产生对精神分裂症注意力问题特别敏感的测试。
预测得到部分证实。尽管在大多数情况下,增加情境要求并未导致患者表现出现不成比例的减慢,但错误数据在很大程度上与预测一致。同时,数据并未表明存在简单的单一情境缺陷。相反,情境的不同方面——情境信息必须在脑海中保持的时间以及情境的一致性——在不同任务中具有不同的重要性。
精神分裂症患者的认知障碍不能简单地被描述为普遍的情境缺陷。这表明了一幅更具差异性(即便不是任务特异性)的精神分裂症缺陷图景。