Prefrontal tDCS Attenuates Self-Referential Attentional Deployment: A Mechanism Underlying Adaptive Emotional Reactivity to Social-Evaluative Threat

Abstract

Social-evaluative threat (SET) – a situation in which one could be negatively evaluated by others – elicits profound (psycho)physiological reactivity which, if chronically present and not adaptively regulated, has deleterious effects on mental and physical health. Decreased self-awareness and increased other-awareness are understood to be an adaptive response to SET. Attentional deployment – the process of selectively attending to certain aspects of emotional stimuli to modulate emotional reactivity – is supported by fronto-parietal and fronto-limbic networks, with the dorsolateral prefrontal cortex being a central hub. The primary aim of the current study was to investigate the effects of active (versus sham) prefrontal transcranial direct current stimulation (tDCS) on self and other-attentional deployment during the exposure to a SET context. Seventy-four female participants received active or sham tDCS and were subsequently exposed to a rigged social feedback paradigm. In this paradigm a series of social evaluations were presented together with a photograph of the supposed evaluator and a self- photograph of the participant, while gaze behavior (time to first fixation, total fixation time) and skin conductance responses (SCRs; a marker of emotional reactivity) were measured. For half of the evaluations, participants could anticipate the valence (negative or positive) of the evaluation a priori. Analyses showed that participants receiving active tDCS were (a) slower to fixate on their self-photograph, (b) spent less time fixating on their self-photograph, and (c) spent more time fixating on the evaluator photograph. During unanticipated evaluations, active tDCS was associated with less time spent fixating on the evaluation. Furthermore, among those receiving active tDCS, SCRs were attenuated as a function of slower times to fixate on the self-photograph. Taken together, these results suggest that in a context of SET, prefrontal tDCS decreases self-attention while increasing other-attention, and that attenuated self-referential attention specifically may be a neurocognitive mechanism through which tDCS reduces emotional reactivity. Moreover, the results suggest that tDCS reduces vigilance toward stimuli that possibly convey threatening information, corroborating past research in this area.

Reduced Attention Towards Accomplishments Mediates the Effect of Self-Critical Rumination on Regret

“…Furthermore, focusing more on what actually happened (i.e., factual information), may help to more quickly come to terms with the current circumstances, and possibly promote self-acceptance and self-compassion, which are protective mechanisms against maladaptive self-blame regret (Cheng & Lin, 2016;Zhang & Chen, 2016). In addition, non-invasive brain stimulation (e.g., transcranial direct current stimulation; tDCS) targeting the neural circuitry involved in selective attention (i.e., frontoparietal cognitive control network) has shown adaptive effects on attentional processes and attenuates emotional reactivity to emotional stimuli (Allaert et al, 2021b;Mondino et al, 2015;Smits et al, 2020). Furthermore, prefrontal tDCS has been shown to attenuate counterfactual thinking and regret, specifically among individuals prone to self-critical rumination (Allaert et al, 2021a).…”

Combining transcranial direct current stimulation with group cognitive behavioral therapy developed to treat rumination: a clinical pilot study

“…Within the clinical context, the effect of tDCS on reducing rumination on sadness was demonstrated in patients with drug-resistant depression ( 23 ). Studies in healthy populations indicate that (even one) left anodal DLPFC tDCS session can attenuate momentary ruminative self-referential thoughts ( 24 , 25 ) as well as self-attention ( 26 ). It is hypothesized that attenuated self-referential attention specifically may be a neurocognitive mechanism through which tDCS reduces emotional reactivity ( 26 ).…”