Dolcos Florin, LaBar Kevin S, Cabeza Roberto
Center for Cognitive Neuroscience, Duke University, Durham, NC 27708-0999, USA.
Neuroimage. 2004 Sep;23(1):64-74. doi: 10.1016/j.neuroimage.2004.05.015.
Prefrontal cortex (PFC) activity associated with emotional evaluation and subsequent memory was investigated with event-related functional MRI (fMRI). Participants were scanned while rating the pleasantness of emotionally positive, negative, and neutral pictures, and memory for the pictures was tested after scanning. Emotional evaluation was measured by comparing activity during the picture rating task relative to baseline, and successful encoding was measured by comparing activity for subsequently remembered versus forgotten pictures (Dm effect). The effect of arousal on these measures was indicated by greater activity for both positive and negative pictures than for neutral ones, and the effect of valence was indicated by differences in activity between positive and negative pictures. The study yielded three main results. First, consistent with the valence hypothesis, specific regions in left dorsolateral PFC were more activated for positive than for negative picture evaluation, whereas regions in right ventrolateral PFC showed the converse pattern. Second, dorsomedial PFC activity was sensitive to emotional arousal, whereas ventromedial PFC activity was sensitive to positive valence, consistent with evidence linking these regions, respectively, to emotional processing and self-awareness or appetitive behavior. Finally, successful encoding (Dm) activity in left ventrolateral and dorsolateral PFC was greater for arousing than for neutral pictures. This finding suggests that the enhancing effect of emotion on memory formation is partly due to an augmentation of PFC-mediated strategic, semantic, and working memory operations. These results underscore the critical role of PFC in emotional evaluation and memory, and disentangle the effects of arousal and valence across PFC regions associated with different cognitive functions.
采用事件相关功能磁共振成像（fMRI）研究了与情绪评估及后续记忆相关的前额叶皮质（PFC）活动。在参与者对情绪积极、消极和中性图片的愉悦度进行评分时对其进行扫描，并在扫描后测试他们对图片的记忆。通过比较图片评分任务期间相对于基线的活动来测量情绪评估，通过比较后续记住的图片与遗忘的图片的活动来测量成功编码（差异记忆效应）。积极和消极图片的活动均高于中性图片，这表明了唤醒对这些测量指标的影响，而积极和消极图片之间的活动差异则表明了效价的影响。该研究产生了三个主要结果。首先，与效价假设一致，左侧背外侧前额叶皮质的特定区域在评估积极图片时比评估消极图片时更活跃，而右侧腹外侧前额叶皮质的区域则呈现相反的模式。其次，背内侧前额叶皮质的活动对情绪唤醒敏感，而腹内侧前额叶皮质的活动对积极效价敏感，这分别与将这些区域与情绪加工以及自我意识或欲望行为联系起来的证据一致。最后，左侧腹外侧和背外侧前额叶皮质中成功编码（差异记忆效应）的活动在处理唤起性图片时比处理中性图片时更强。这一发现表明，情绪对记忆形成的增强作用部分归因于前额叶皮质介导的策略性、语义性和工作记忆操作的增强。这些结果强调了前额叶皮质在情绪评估和记忆中的关键作用，并厘清了与不同认知功能相关的前额叶皮质区域中唤醒和效价的影响。
