The role of dorsolateral and ventromedial prefrontal cortex in the processing of emotional dimensions

Vahid Nejati,Reyhaneh Majdi,Mohammad Ali Salehinejad,Michael A Nitsche

doi:10.1038/s41598-021-81454-7

Abstract

The ventromedial and dorsolateral prefrontal cortex are two major prefrontal regions that usually interact in serving different cognitive functions. On the other hand, these regions are also involved in cognitive processing of emotions but their contribution to emotional processing is not well-studied. In the present study, we investigated the role of these regions in three dimensions (valence, arousal and dominance) of emotional processing of stimuli via ratings of visual stimuli performed by the study participants on these dimensions. Twenty- two healthy adult participants (mean age 25.21 ± 3.84 years) were recruited and received anodal and sham transcranial direct current stimulation (tDCS) (1.5 mA, 15 min) over the dorsolateral prefrontal cortex (dlPFC) and and ventromedial prefrontal cortex (vmPFC) in three separate sessions with an at least 72-h interval. During stimulation, participants underwent an emotional task in each stimulation condition. The task included 100 visual stimuli and participants were asked to rate them with respect to valence, arousal, and dominance. Results show a significant effect of stimulation condition on different aspects of emotional processing. Specifically, anodal tDCS over the dlPFC significantly reduced valence attribution for positive pictures. In contrast, anodal tDCS over the vmPFC significantly reduced arousal ratings. Dominance ratings were not affected by the intervention. Our results suggest that the dlPFC is involved in control and regulation of valence of emotional experiences, while the vmPFC might be involved in the extinction of arousal caused by emotional stimuli. Our findings implicate dimension-specific processing of emotions by different prefrontal areas which has implications for disorders characterized by emotional disturbances such as anxiety or mood disorders.

Highlights

The ventromedial and dorsolateral prefrontal cortex are two major prefrontal regions that usually interact in serving different cognitive functions
The perceived side effects were not significantly different between stimulation conditions, except for the item “burning sensation”, which was rated significantly higher for anodal left dorsolateral prefrontal cortex (dlPFC) transcranial direct current stimulation (tDCS) (p = 0.037), as compared with the sham condition
The results of this study suggest a discernable contribution of the dlPFC and ventromedial prefrontal cortex (vmPFC) on the differential emotional evaluation of visual stimuli

Summary

Introduction

The ventromedial and dorsolateral prefrontal cortex are two major prefrontal regions that usually interact in serving different cognitive functions. The vmPFC is sensitive to the reward or value of stimuli[9,10], value-based decision-making[11], anticipation of reward[12] and self-based evaluation[13] To put it in a nutshell, the vmPFC is assumed to have a crucial role in emotional processing, whereas the dlPFC is predominantly involved in cognitive control and executive processing. It is debatable if such a strict functional distinction of the respective areas does hold. Hypothesis, functional imaging studies show a gradual transition between ventromedial, and dorsolateral prefrontal areas with regard to emotion processing[17]

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