Kaneda Takumi, Shigemune Yayoi, Tsukiura Takashi
Department of Cognitive and Behavioral Sciences, Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-Nihonmatsu-Cho, Sakyo-ku, Kyoto, 606-8501, Japan.
Cogn Affect Behav Neurosci. 2017 Feb;17(1):143-157. doi: 10.3758/s13415-016-0468-6.
Memories for emotion-laden stimuli are remembered more accurately than those for neutral stimuli. Although this enhancement reflects stimulus-driven modulation of memory by emotions, functional neuroimaging evidence of the interacting mechanisms between emotions generated by intentional processes, such as semantic elaboration, and memory is scarce. The present fMRI study investigated how encoding-related activation is modulated by emotions generated during the process of semantic elaboration. During encoding with fMRI, healthy young adults viewed neutral (target) pictures either passively or with semantic elaboration. In semantic elaboration, participants imagined background stories related to the pictures. Encoding trials with semantic elaboration were subdivided into conditions in which participants imagined negative, positive, or neutral stories. One week later, memories for target pictures were tested. In behavioral results, memories for target pictures were significantly enhanced by semantic elaboration, compared to passive viewing, and the memory enhancement was more remarkable when negative or positive stories were imagined. fMRI results demonstrated that activations in the left inferior frontal gyrus and dorsal medial prefrontal cortex (dmPFC) were greater during the encoding of target pictures with semantic elaboration than those with passive viewing, and that these activations further increased during encoding with semantic elaboration of emotional stories than of neutral stories. Functional connectivity between the left inferior frontal gyrus and dmPFC/hippocampus during encoding significantly predicted retrieval accuracies of memories encoded with self-generated emotional stories. These findings suggest that networks including the left inferior frontal region, dmPFC, and hippocampus could contribute to the modulation of memories encoded with the emotion generation.
与中性刺激相比，带有情感色彩的刺激记忆得更准确。虽然这种增强反映了情感对记忆的刺激驱动调节，但关于有意过程（如意义阐述）产生的情感与记忆之间相互作用机制的功能神经影像学证据却很少。本功能磁共振成像（fMRI）研究调查了在语义阐述过程中产生的情感如何调节与编码相关的激活。在fMRI编码期间，健康的年轻成年人被动地或通过语义阐述观看中性（目标）图片。在语义阐述过程中，参与者想象与图片相关的背景故事。带有语义阐述的编码试验被细分为参与者想象消极、积极或中性故事的条件。一周后，对目标图片的记忆进行测试。行为结果显示，与被动观看相比，语义阐述显著增强了对目标图片的记忆，并且当想象消极或积极故事时，记忆增强更为显著。fMRI结果表明，在对目标图片进行语义阐述编码时，左下额叶回和背内侧前额叶皮质（dmPFC）的激活比被动观看时更强，并且在对情感故事而非中性故事进行语义阐述编码时，这些激活进一步增加。编码期间左下额叶回与dmPFC/海马体之间的功能连接显著预测了用自我生成的情感故事编码的记忆的检索准确性。这些发现表明，包括左下额叶区域、dmPFC和海马体在内的神经网络可能有助于调节由情感产生所编码的记忆。
