The following is a summary of “Neuroticism modulates the qualitative effects of inferior parietal tDCS on negatively-valenced memories,” published in the May 2023 issue of Psychiatric Research by Hayden et al.
Receiving criticism or negative feedback has been associated with worse psychological and cognitive outcomes for individuals with elevated levels of neuroticism. Transcranial direct current stimulation (tDCS) can alter cognitive processes in clinical populations. Researchers bilaterally stimulated the posterior inferior parietal lobule (pIPL), a critical superficial node in the default model network. After hearing criticism, they investigated how baseline neuroticism modulates the effect of bilateral tDCS to pIPL on qualitative memory measures.
Investigators hypothesized that cathodal stimulation of the IPL would enhance memory quality for individuals with higher levels of neuroticism. About 90 community members were randomly assigned to receive anodal, cathodal, or placebo stimulation while exposed to critical comments before and after stimulation. The participants were then asked to recall the critical comments. Their linguistic responses were analyzed using Pennebaker’s Linguistic Inquiry and Word Count software, a quantitative analysis software for linguistic data.
Higher neuroticism scores correlated with increased proportions of non-personal language (i.e., “us,” “they,” or “other” instead of “I” or “me”) when recalling negative feedback among individuals receiving cathodal tDCS. Cathodal tDCS stimulation of the pIPL, as opposed to anodal or placebo stimulation, increased emotional distancing and perspective-taking strategies when recalling criticism in individuals with higher neuroticism. These findings highlight the state-dependent nature of tDCS effects and the function of the IPL in interpersonal processing – a clinically relevant finding not revealed by current tDCS studies examining only quantitative measures of memory (e.g., task-based accuracy or speed).