Center for Psychiatric Research, Beijing Huilongguan Hospital, Beijing 100096, China.
Schizophr Res. 2011 Dec;133(1-3):112-9. doi: 10.1016/j.schres.2011.09.017. Epub 2011 Oct 19.
The present study combined a time-locked paradigm and high-time-resolution event-related potential (ERP) recordings to examine different phases of working memory, including early visual processing and late memory-related processes of encoding, maintenance, and retrieval, in 67 adults with schizophrenia and 46 healthy controls. Alterations in ERP components were correlated with task performance. Patients performed significantly worse in the working memory task than healthy subjects, although all subjects' accuracy exceeded 80%. During encoding, the N1 and P2 component amplitudes were lower while the P300 amplitude was higher in schizophrenic patients compared to healthy controls. There were no differences between groups with respect to the mean amplitudes of the negative slow waves in the early stage (the first 400 ms) of the maintenance phase. However, in the next 500-ms time window, the patients exhibited a more negative deflection in the middle fronto-central region than the control group. Likewise, a similar pattern was observed in the second 500-ms period in the middle fronto-central region, although the effect was marginally significant. There were no differences between groups in the remaining 1000 ms. During retrieval, the P1, N1 and P2 amplitudes were lower while the P300 amplitude and latency were higher in schizophrenic patients. The present results indicate early visual deficits in the working memory task in adults with schizophrenia. Impairments in the maintenance phase were confined to the late rehearsal stage. The increased P300 amplitude at the fronto-central electrode sites along with the poorer behavioral performance suggests that schizophrenic patients have an inefficient working memory system.
本研究采用时间锁定范式和高时间分辨率事件相关电位（ERP）记录，对 67 名精神分裂症患者和 46 名健康对照者的工作记忆的不同阶段，包括早期视觉处理和后期与记忆相关的编码、维持和提取过程，进行了研究。ERP 成分的变化与任务表现相关。患者在工作记忆任务中的表现明显差于健康受试者，尽管所有受试者的准确率都超过 80%。在编码阶段，与健康对照组相比，精神分裂症患者的 N1 和 P2 成分振幅较低，而 P300 振幅较高。在维持阶段早期（前 400 毫秒），两组之间的负慢波平均振幅没有差异。然而，在下一个 500 毫秒的时间窗口中，患者在中额-中央区域的负向偏转比对照组更大。同样，在中额-中央区域的第二个 500 毫秒时间窗口中也观察到了类似的模式，尽管效果略有显著。在剩余的 1000 毫秒时间内，两组之间没有差异。在提取阶段，精神分裂症患者的 P1、N1 和 P2 振幅较低，而 P300 振幅和潜伏期较高。本研究结果表明，成人精神分裂症患者在工作记忆任务中存在早期视觉缺陷。维持阶段的损伤仅限于晚期复述阶段。额-中央电极部位 P300 振幅增加和行为表现较差表明，精神分裂症患者的工作记忆系统效率较低。
