fMRI identifies a network of structures correlated with retention of positive and negative emotional memory

It is likely that the encoding of emotional experiences involves a complex network of interacting brain regions. The present study used fMRI to identi fy brain structures involved in the encoding of negative and positive emoti onal stimuli. Ten subjects viewed alternating blocks of emotionally negativ e and positive pictures and were tested for long-term recognition memory se veral months later. Recognition memory for negative and positive pictures w as highly correlated. Brain reactivity to negative pictures was positively correlated with better recognition memory for both negative and positive pi ctures in the amygdala, the insula, and the right middle frontal gyrus. Bra in reactivity to positive pictures was positively correlated with better re cognition memory for both negative and positive pictures in the left anteri or cingulate gyrus. Activation among these brain regions was highly correla ted and suggests a network of structures that interact to encode either neg ative or positive emotional stimuli for longterm recognition memory. Two me chanisms by which this encoding may take place are discussed.