Functional specificity of the left ventrolateral prefrontal cortex in positive reappraisal: A single-pulse transcranial magnetic stimulation study

Abstract

Neuroimage studies have yielded evidence for a correlation between the left ventrolateral prefrontal cortex (VLPFC) and a specific type of cognitive reappraisal strategy, positive reappraisal. However, evidence is still lacking for a direct relation. We used single-pulse transcranial magnetic stimulation (TMS) over the left VLPFC at different time points to investigate the functional specificity of the left VLPFC in the success of positive reappraisal and the timing at which the left VLPC was involved in positive reappraisal. Fifteen participants engaged in a baseline experiment and in TMS experiments. All participants successfully reduced their negative emotional ratings using positive reappraisal in the baseline experiment. In the TMS experiments, participants performed the same task as in the baseline experiment but single-pulse TMS was applied over the left VLPFC at 300 ms or/and 3,300 ms after stimulus onset, as well as over the vertex as a control stimulation. Valence ratings of negative stimuli increased (unpleasantness reduction) when participants reappraised negative stimuli with TMS stimulation over the left VLPFC, regardless of the timing of the stimulation at 300 ms or/and at 3,300 ms after the stimulus onset, relative to the vertex stimulation and the baseline experiment. Our study provided evidence of the functional specificity of the left VLPFC in regulation of negative emotions using positive reappraisal. The left VLPFC was believed to be involved in different stages of positive reappraisal. The prominent facilitation effect of TMS over the left VLPFC makes it possible to consider potential applications in clinical practice for mood disorders.