Laboratory for Neurology & Imaging of Cognition, Department of Neurosciences & Neurology, University Hospital and Medical School, University of Geneva, Switzerland Swiss Center for Affective Sciences, University of Geneva, Switzerland.
Neuroimage. 2012 Apr 15;60(3):1734-45. doi: 10.1016/j.neuroimage.2012.01.110. Epub 2012 Jan 28.
Studies on memory retrieval suggest a reactivation of cortical regions engaged during encoding, such that visual or auditory areas reactivate for visual or auditory memories. The content specificity and any emotion dependency of such reactivations are still unclear. Because distinct visual areas are specialized in processing distinct stimulus categories, we tested for face and word specific reactivations during a memory task using functional magnetic resonance imaging (fMRI). Furthermore, because visual processing and memory are both modulated by emotion, we compared reactivation for stimuli encoded in a neutral or emotionally significant context. In the learning phase, participants studied pairs of stimuli that consisted of either a scene and a face, or a scene and a word. Scenes were either neutral or negative, but did not contain faces or words. In the test phase scenes were presented alone (one in turn), and participants indicated whether it was previously paired with a face, a word, or was new. Results from the test phase showed activation in a functionally defined face-responsive region in the right fusiform gyrus, as well as in a word-responsive region in the left inferior temporal gyrus, for scenes previously paired with faces and words, respectively. Reactivation tended to be larger in both the face- and word-responsive regions when the associated scene was negative as compared to neutral. However, relative to neutral context, the recall of faces and words paired with a negative context produced smaller activations in brain regions associated with social and semantic processing, respectively, as well as poorer memory performance overall. Taken together, these results support the idea of cortical memory reactivations, even at a content-specific level, and further suggest that emotional context may produce opposite effects on reactivations in early sensory areas and more elaborate processing in higher-level cortical areas.
记忆检索研究表明，在编码过程中会重新激活大脑皮层区域，从而使视觉或听觉区域重新激活以获取视觉或听觉记忆。但是，这种重新激活的内容特异性和任何情感依赖性仍然不清楚。由于不同的视觉区域专门用于处理不同的刺激类别，因此我们使用功能磁共振成像（fMRI）在记忆任务中测试了面孔和单词的特定重新激活。此外，由于视觉处理和记忆都受到情绪的调节，因此我们比较了在中性或情感重要的背景下编码的刺激的重新激活。在学习阶段，参与者研究了由场景和面孔或场景和单词组成的刺激对。场景要么是中性的，要么是消极的，但不包含面孔或单词。在测试阶段，场景单独呈现（一个接一个），参与者表示它是否以前与面孔，单词或新的场景配对过。测试阶段的结果显示，在右侧梭状回中定义为功能的面孔反应区域以及在左侧颞下回中定义为单词反应区域中，分别激活了与面孔和单词配对的场景。与中性背景相比，当相关场景为负面时，两个面孔和单词反应区域中的重新激活均倾向于更大。但是，与中性上下文相比，与负面上下文配对的面孔和单词的回忆会导致与社会和语义处理相关的大脑区域的激活减少，分别为，并且整体记忆性能较差。综上所述，这些结果支持了皮质记忆重新激活的观点，即使在内容特异性水平上也是如此，并且进一步表明情绪背景可能会对早期感觉区域中的重新激活以及更高水平的皮质区域中的更精细的处理产生相反的影响。
