Delawalla Zainab, Csernansky John G, Barch Deanna M
Department of Psychology, Washington University, St. Louis, Missouri 63130, USA.
Biol Psychiatry. 2008 Mar 1;63(5):490-7. doi: 10.1016/j.biopsych.2007.05.007. Epub 2007 Jul 16.
Cognitive dysfunction is a hallmark feature of schizophrenia. In recent years, it has been proposed that impairments in attention, working memory and executive function may all reflect an underlying deficit in context processing. In individuals with schizophrenia, deficits in context processing have been associated with functional impairments of the dorsolateral prefrontal cortex (DLPFC).
We used a variation of the continuous performance task, the AX-CPT, to test the hypothesis that genetic high-risk individuals (full siblings of individuals with schizophrenia) have deficits in context processing and abnormal activation of the DLPFC as compared to community controls.
Siblings of individuals with schizophrenia made significantly more B-X errors on the AX-CPT, indicative of a deficit in context processing. They also showed task-related hyper-activation in a number of brain regions, including the DLPFC.
Inefficient hyper-activation of the DLPFC may underlie deficits in context processing and contribute to the genetic vulnerability for developing schizophrenia.
认知功能障碍是精神分裂症的一个标志性特征。近年来,有人提出注意力、工作记忆和执行功能的损害可能都反映了情境加工方面的潜在缺陷。在精神分裂症患者中,情境加工缺陷与背外侧前额叶皮质(DLPFC)的功能损害有关。
我们使用了连续性能任务的一种变体,即AX-CPT,来检验以下假设:与社区对照相比,遗传高危个体(精神分裂症患者的全同胞)在情境加工方面存在缺陷,且DLPFC激活异常。
精神分裂症患者的同胞在AX-CPT上出现的B-X错误显著更多,这表明情境加工存在缺陷。他们在包括DLPFC在内的多个脑区还表现出与任务相关的过度激活。
DLPFC的低效过度激活可能是情境加工缺陷的基础,并导致患精神分裂症的遗传易感性。