University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Int J Psychophysiol. 2010 Feb;75(2):107-18. doi: 10.1016/j.ijpsycho.2008.04.008. Epub 2009 Dec 11.
Sustained and elaborative emotional information processing in depression and decreased affective elaboration in schizophrenia are considered hallmarks of these disorders but have not been directly measured. Gamma-band (35-45 Hz) EEG has been associated with semantic functions such as feature binding and may index these elaborative processing. This study examined whether there were group differences in baseline and sustained gamma-band EEG following emotional stimuli in healthy adults as well as adults with depression and schizophrenia.
24 never-depressed healthy controls, 14 patients with DSM-IV unipolar major depressive disorder, and 15 patients with DSM-IV schizophrenia completed a lexical emotion identification task during EEG assessment. Gamma-band (35-45 Hz) EEG in response to negative words was the primary dependent measure.
As predicted, depressed individuals displayed sustained and increased gamma-band EEG throughout the task, and particularly in the seconds following negative words. Individuals with schizophrenia displayed decreased gamma-band activity throughout the task.
These data suggest that gamma-band EEG, measured over several seconds, may serve as a useful index of sustained semantic information processing. Depressed individuals appear to engage in sustained elaboration following emotional stimuli, whereas individuals with schizophrenia are not as prone to this type of elaborative processing.
抑郁症患者持续且详尽地处理情绪信息，精神分裂症患者的情感详尽度降低，这被认为是这些疾病的特征，但尚未直接测量。γ 波段（35-45Hz）脑电图与语义功能（如特征绑定）有关，可能会对这些详尽的处理进行索引。本研究检测了在情绪刺激后，健康成年人、抑郁症患者和精神分裂症患者的基线和持续 γ 波段脑电图是否存在组间差异。
24 名从未患过抑郁症的健康对照者、14 名符合 DSM-IV 单相重性抑郁障碍的患者和 15 名符合 DSM-IV 精神分裂症的患者在脑电图评估期间完成了词汇情绪识别任务。负性词语诱发的 γ 波段（35-45Hz）脑电图是主要的因变量。
正如预测的那样，抑郁组在整个任务中都表现出持续且增强的 γ 波段脑电图，尤其是在负性词语之后的几秒钟内。精神分裂症组在整个任务中都表现出 γ 波段活动减少。
这些数据表明，γ 波段脑电图（在数秒内测量）可作为持续语义信息处理的有用指标。抑郁组在情绪刺激后似乎会进行持续的详尽处理，而精神分裂症组则不太倾向于这种详尽的处理方式。
