Examining the Role of Lateral Parietal Cortex in Emotional Distancing Using TMS

We recently proposed a neurocognitive model of distancing-an emotion regulation tactic-with a focus on the lateral parietal cortex. Although this brain area has been implicated in both cognitive control and self-projection processes during distancing, fMRI work suggests that these processes may be dissociable here. This preregistered (NCT03698591) study tested the contribution of left temporoparietal junction (TPJ) to distancing using repetitive transcranial magnetic stimulation. We hypothesized that inhibiting left TPJ would decrease the efficiency of distancing but not distraction, another regulation tactic with similar cognitive control requirements, thus implicating this region in the self-projection processes unique to distancing. Active and sham continuous theta burst stimulation (cTBS) were applied to 30 healthy adults in a single-session crossover design. Tactic efficiency was measured using online reports of valence and effort. The stimulation target was established from the group TPJ fMRI activation peak in an independent sample using the same distancing task, and anatomical MRI scans were used for individual targeting. Analyses employed both repeated-measures ANOVA and analytic procedures tailored to crossover designs. Irrespective of cTBS, distancing led to greater decreases in negative valence over time relative to distraction, and distancing effort decreased over time while distraction effort remained stable. Exploratory analyses also revealed that active cTBS made distancing more effortful, but not distraction. Thus, left TPJ seems to support self-projection processes in distancing, and these processes may be facilitated by repeated use. These findings help to clarify the role of lateral parietal cortex in distancing and inform applications of distancing and distraction.