Fig. 4: The effects of bilateral DLPFC anodal tDCS and HF-tRNS on positive and negative emotional affect, along with their association with cognitive function.

Both bilateral DLPFC anodal tDCS and bilateral DLPFC HF-tRNS, but not sham tES, significantly increased positive affect and decreased negative affect post-intervention. Only significant correlations are presented. A, B show that emotional stability before the intervention showed no significant differences across stimulation conditions, while both bilateral DLPFC anodal tDCS and HF-tRNS significantly reduced negative affect and also increased positive affect. Filled symbols indicate a significant difference between post- and pre-intervention, while [*] denotes a significant difference compared to sham. C–H present scatterplots of patients’ post-intervention cognitive performance and negative affect, showcasing only significant comparisons. In C, an increase in solved problems after the intervention (represented by darker green nodes) correlates with lower PANAS-negative affect scores (closer to 15), suggesting that improved executive function is associated with reduced negative affect. In D, a lower number of moves required to solve problems (darker green nodes) correlates with lower PANAS-negative affect scores (closer to 15), indicating that better performance in the SOC task may also be linked to reduced negative affect. Scatterplots E, F and G, H depict similar data but show no significant results for the bilateral anodal tDCS and sham conditions.