Abstract
Background and objectivesThe Dorsolateral prefrontal cortex (DLPFC) is implicated in cognitive and emotional responses. Yet, research that investigates the causal role of the left versus right DLPFC during the processes of emotion appraisal is lacking. In the current study, transcranial direct current stimulation (tDCS) was used to disentangle the functional lateralization of the DLPFC on emotional processing in response to the anticipation of, and subsequent confrontation with emotional stimuli in healthy volunteers.MethodsForty-eight subjects received both active and sham (on separate days) anodal tDCS over either the left (N = 24) or right (N = 24) DLPFC. Subjects’ pupil dilation (PD, a physiological marker of cognitive resource allocation) was recorded while performing an appraisal task in which negative and positive emotion eliciting images were presented, each preceded by an informative cue indicating the valence of the upcoming stimulus.ResultsAs compared to sham stimulation, left DLPFC anodal tDCS resulted in increased PD when confronted with negative emotional images, whereas right DLPFC anodal tDCS resulted in decreased PD when confronted with emotional images, irrespective of valence.LimitationsThe interpretation of pupil dilation in response to emotional stimuli is limited.ConclusionThese findings suggest inverse lateralized DLPFC effects on cognitive resource allocation (as measured by pupillary responses) when confronted with emotional stimuli. The current findings may shed some light on mechanisms that explain the antidepressant effects of non-invasive brain stimulation of the left DLPFC.
Highlights
The regulation of emotional responses is essential for subjective wellbeing [1], and plays an important part in dealing with daily life hassles
As compared to sham stimulation, left dorsolateral prefrontal cortex (DLPFC) anodal transcranial direct current stimulation (tDCS) resulted in increased PD when confronted with negative emotional images, whereas right DLPFC anodal tDCS resulted in decreased PD when confronted with emotional images, irrespective of valence
The interpretation of pupil dilation in response to emotional stimuli is limited. These findings suggest inverse lateralized DLPFC effects on cognitive resource allocation when confronted with emotional stimuli
Summary
The regulation of emotional responses is essential for subjective wellbeing [1], and plays an important part in dealing with daily life hassles. It has been shown that when individuals are instructed to down-regulate their emotional responses towards emotional stimuli (i.e., reappraisal), activity in the DLPFC increases, while activity in the amygdala and self-reported negative affect decreases [5]. Patients with mood disorders are characterized by a functional hemispheric imbalance of the DLPFC, with hyperactivity of the right DLPFC and hypoactivity of the left DLPFC [9]. By using non-invasive brain stimulation (NIBS) techniques, augmenting activity in the left DLPFC or reducing activity in the right DLPFC has been shown to decrease depressive symptoms (for a review, see [10]). Research in healthy volunteers showed that anodal (i.e., excitatory) tDCS over the left DLPFC decreased emotional reactivity towards negative stimuli, as measured by both behavioral [11, 12], and psychophysiological [13] assessment methods
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
