Deactivation of the attention-shifting ventromedial prefrontal cortex during the encoding and hold phases predicts working memory performance

Abstract

Objectives Recent neuroimaging studies have suggested that the deactivation of the ventromedial prefrontal cortex (VMPFC) works with the attention shifting area to facilitate the encoding of behaviorally relevant inputs. These findings have led to the notion that the deactivation of VMPFC substantially contributes to the cognitive control of emotions. Although VMPFC deactivation during working memory tasks is established, whether it contributes to performance in emotionally distracted working memory tasks remains unclear. This study aimed to investigate whether the magnitude of VMPFC deactivation predicts better performance in emotionally distracted working memory tasks. Methods Twenty-nine female participants performed delayed-response working memory tasks with emotional distracters presented during the hold phase of working memory while undergoing functional MRI. A GLM and a paired t-test were used to observe brain responses to emotional distracters. The correlation between brain response and working memory performance was also computed to investigate brain areas that predict working memory performance in emotionally distracted tasks. Results Three trends in brain activity were strongly correlated with high working memory performance: (1) increased activity in cognitive control areas (dorsolateral prefrontal cortex), (2) lower activity in emotional reactivity areas (fusiform gyrus), and (3) deactivation of the attention shifting area, mainly VMPFC. In addition, all three trends correlated with high working memory performance during the hold phase of working memory, whereas only (2) and (3) correlated with high working memory performance during the encoding phase. Conclusions These results provide further evidence of the functional importance of VMPFC and demonstrate that VMPFC deactivation is particularly important during the encoding and hold phases of working memory.