Patrick Regan E, Kiang Michael, Christensen Bruce K
McMaster University, Department of Psychiatry & Behavioural Neuroscience, 1280 Main St. W., Hamilton, ON L8S 4 L8, Canada; McMaster University, McMaster Integrative Neuroscience Discovery & Study (MiNDS), 1280 Main St. W., Hamilton, ON L8S 4 L8, Canada; McMaster University, Department of Psychology, Neuroscience, & Behaviour, 1280 Main St. W., Hamilton, ON L8S 4 L8, Canada.
McMaster University, Department of Psychiatry & Behavioural Neuroscience, 1280 Main St. W., Hamilton, ON L8S 4 L8, Canada; McMaster University, McMaster Integrative Neuroscience Discovery & Study (MiNDS), 1280 Main St. W., Hamilton, ON L8S 4 L8, Canada; University of Toronto, Department of Psychiatry, 172 St. George St., Toronto, ON M5R 0A3, Canada.
Int J Psychophysiol. 2015 Dec;98(3 Pt 2):612-23. doi: 10.1016/j.ijpsycho.2015.01.006. Epub 2015 Jan 22.
Recent research has shown that patients with schizophrenia (SCZ) exhibit reduced directed forgetting (DF) for negative words, suggesting impaired ability to instantiate goal-directed inhibition in order to suppress a competing, emotion-driven responses (i.e., emotional memory enhancement). However, disrupted inhibition is not the only possible mechanism by which patients could manifest reduced emotional DF. Therefore, the primary objective of the current study was to use event-related brain potential (ERP) recordings to investigate alternative hypotheses.
ERPs were recorded while patients and controls completed an item-method DF paradigm using negative and neutral words. The N2 indexed goal-directed inhibition of to-be-forgotten items. The late positive potential (LPP) indexed emotional memory enhancement for negative study items. The P300 indexed selective rehearsal of to-be-remembered items.
The SCZ group exhibited a reduced DF effect overall, but this was not modulated by emotion. N2 amplitude at anterior sites was larger for forget versus remember cues in the control group only, but this effect was not modulated by emotion. LPP amplitude was greater for negative versus neutral words in both groups, independent of region. P300 amplitude at posterior sites was greater for remember versus forget cues in the control group only.
These data suggest that reduced DF in SCZ may be due, in part, to both diminished goal-directed inhibition of to-be-forgotten items and reduced selective rehearsal of to-be-remembered items. However, these data do not support the hypothesis that goal-directed, inhibitory processes are disrupted by competing, emotion-driven processes in SCZ. Patients' ERP data also suggested that they did not exhibit disproportionately heightened encoding of emotional stimuli, nor did they have deficient selective rehearsal of to-be-remembered emotional items.
最近的研究表明，精神分裂症（SCZ）患者对负面词汇的定向遗忘（DF）能力下降，这表明他们在为抑制竞争性的、由情感驱动的反应（即情绪记忆增强）而实施目标导向抑制方面存在能力受损。然而，抑制功能紊乱并非患者表现出情绪性定向遗忘减少的唯一可能机制。因此，本研究的主要目的是使用事件相关脑电位（ERP）记录来探究其他假设。
在患者和对照组使用负面和中性词汇完成项目法定向遗忘范式时记录ERP。N2指标反映对要遗忘项目的目标导向抑制。晚期正电位（LPP）指标反映对负面学习项目的情绪记忆增强。P300指标反映对要记住项目的选择性复述。
SCZ组总体上表现出定向遗忘效应降低，但这并未受到情绪的调节。仅在对照组中，前位部位的N2波幅在遗忘线索与记住线索之间更大，但这种效应未受到情绪的调节。两组中，负面词汇的LPP波幅均大于中性词汇，与区域无关。仅在对照组中，后位部位的P300波幅在记住线索与遗忘线索之间更大。
这些数据表明，SCZ患者定向遗忘减少可能部分归因于对要遗忘项目的目标导向抑制减弱以及对要记住项目的选择性复述减少。然而，这些数据并不支持以下假设，即目标导向的抑制过程在SCZ中被竞争性的、由情感驱动的过程所扰乱。患者的ERP数据还表明，他们对情绪刺激的编码没有过度增强，对要记住的情绪项目也没有选择性复述缺陷。
