Servan-Schreiber D, Cohen J D, Steingard S
Department of Psychiatry, University of Pittsburgh, Pa, USA.
Arch Gen Psychiatry. 1996 Dec;53(12):1105-12. doi: 10.1001/archpsyc.1996.01830120037008.
Schizophrenic patients show various deficits in cognitive functions that have been difficult to understand in terms of a common unifying hypothesis. Previously described neural network models of cognitive tasks suggest that several schizophrenic performance deficits may be related to a single function-an impairment in maintaining contextual information over time and in using that information to inhibit inappropriate responses.
We tested first-episode schizophrenic patients and patients later in the course of their illness on a new variant of the Continuous Performance Test designed specifically to elicit deficits in the processing of contextual information.
Unmedicated schizophrenic patients showed a deterioration of their signal detection performance that followed the pattern predicted by the context hypothesis, ie, they responded inappropriately when correct responding required the maintenance of context information over time to inhibit the expression of a habitual response. This deficit correlated with positive symptoms. The results also suggested that the deficit may be worse in unmedicated patients who have had a longer course of illness. Medicated patients showed a more diffuse performance deficit.
These results support the view that a single deficit in the processing of context information may underlie various cognitive impairments observed in schizophrenia. They also suggest that such an impairment is associated with positive rather than negative symptoms, and that it may worsen with the course of the illness as in the kraepelinian view of schizophrenia.
精神分裂症患者在认知功能方面存在多种缺陷，很难用一个统一的假设来解释。先前描述的认知任务神经网络模型表明，精神分裂症的一些表现缺陷可能与单一功能有关，即随着时间推移维持情境信息以及利用该信息抑制不适当反应的能力受损。
我们使用专门设计的连续性能测试新变体，对首发精神分裂症患者和病程较晚阶段的患者进行测试，以引发情境信息处理方面的缺陷。
未服药的精神分裂症患者信号检测表现恶化，符合情境假设所预测的模式，即当正确反应需要随着时间维持情境信息以抑制习惯性反应的表达时，他们会做出不适当反应。这种缺陷与阳性症状相关。结果还表明，病程较长的未服药患者的缺陷可能更严重。服药患者表现出更广泛的表现缺陷。
这些结果支持这样一种观点，即情境信息处理的单一缺陷可能是精神分裂症中观察到的各种认知障碍的基础。它们还表明，这种损害与阳性而非阴性症状相关，并且正如克雷佩林对精神分裂症的看法那样，它可能会随着病程的发展而恶化。
