An FMRI Study Of Emotional Memory

Background and Objective It is well been known that emotionally evocative stimuli are better remembered than neutral stimuli. This phenomenon is called "emotional memory enhancement effect". Emotion can modulate memory process, it is exactly why "emotional memory enhancement effect" happened. There is a common opinion that amygdala plays a critical role in memory consolidation by modulating other related cerebral regions. However, there are some experiments show "emotional enhanced memory" can be observed even after a short interval and it could not be explained only by using memory consolidation. Some researchers propose that "emotional memory enhancement effect" can occur in other different memory-processing phase (like encoding or retrieval phase). It is necessary to make a full understanding about the neural mechanism of the "emotional memory enhancement effect" by studying a series of memory processing phases.It has been demonstrated that emotional events can modulate memory by invocating different neural network corresponding to their emotional arousal or emotional valence level. Adolphs et al examined recognition of two emotional dimemsion, arousal and valence, in a rare patient with complete, bilateral damage restricted to the amygadala. They found that recognition of emotional arousal is impaired for facial expressions, words, and sentences that depict unpleasant emotions. However, recognition of emotional valence was normal. Elizabeth et al have found that distinct cognitive and neural processes contribute to emotional memory enhancement for arousing negative information versus non-arousing negative information. The former depended on an amygdala-hippocampal network, whereas the latter is supported by a prefrontal cortex-hippocampal network. Dolcos and colleages found specific regions in left dorsolateral PFC were more activated for positive picture evaluation, whereas...