Department of Psychological Science, University of California, Irvine, Irvine, CA, United States of America.
Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States of America; MIRECC VISN 4, VA Pittsburgh Healthcare System, Pittsburgh, PA, United States of America.
Schizophr Res. 2019 Feb;204:111-119. doi: 10.1016/j.schres.2018.08.008. Epub 2018 Aug 16.
Some individuals with schizophrenia report similar feelings of positive affect "in the moment" compared to control participants but report decreased trait positive affect overall. One possible explanation for this disconnection between state and trait positive affect is the extent to which individuals with schizophrenia engage in elaborative processing of positive stimuli. To assess this, we examined evoked gamma band activity in response to positive words over several seconds in a group with schizophrenia, a group with major depressive disorder, and a healthy control group. From a pre-stimulus baseline to 2000 ms after onset of the stimulus (henceforth, "early period"), the schizophrenia group showed a reliable increase in gamma activity compared to both the control and depressed groups, who did not differ from each other. In contrast, the depressed group showed a reliable increase in gamma activity from 2001 to 8000 ms (henceforth, "late period") compared to the other groups, who did not differ from each other. At the same time, the schizophrenia group showed a reliable decrease from the early to late period while the depressed group showed the opposite pattern. In addition, self-reported depression and social anhedonia in the schizophrenia group were related to decreased gamma band activity over the entire processing window. Overall, these results suggest that schizophrenia is associated with increased initial reactivity but decreased sustained elaborative processing over time, which could be related to decreased trait positive affect. The results also highlight the importance of considering depressive symptomology and anhedonia when examining emotional abnormalities in schizophrenia.
一些精神分裂症患者在当下体验到的正性情绪感受与对照组相似，但总体上正性特质情绪感受较低。这种状态正性情绪感受与特质正性情绪感受之间的脱节的一个可能解释是精神分裂症患者对正性刺激进行精细加工的程度。为了评估这一点，我们在精神分裂症组、重性抑郁症组和健康对照组中，考察了对正性词语的诱发伽马波段活动，持续数秒。从刺激前基线到刺激后 2000 毫秒（下文简称“早期”），与对照组和抑郁组相比，精神分裂症组的伽马活动有可靠的增加，而对照组和抑郁组之间没有差异。相比之下，抑郁组在 2001 至 8000 毫秒期间（下文简称“晚期”）的伽马活动有可靠的增加，而其他两组之间没有差异。与此同时，精神分裂症组从早期到晚期的伽马活动有可靠的下降，而抑郁组则呈现相反的模式。此外，精神分裂症组的自我报告抑郁和社交快感缺失与整个处理窗口的伽马波段活动减少有关。总的来说，这些结果表明，精神分裂症与初始反应性增加有关，但随着时间的推移，精细加工的持续性下降，这可能与特质正性情绪感受降低有关。这些结果还强调了在研究精神分裂症中的情绪异常时，考虑抑郁症状和快感缺失的重要性。
