Psychosocial Health Following Non-Invasive Brain Stimulation of Oculomotor Regions.

Emotional well-being is an important consideration when applying non-invasive brain stimulation to regions involved in visual and oculomotor control. This study assessed affective changes following transcranial direct current stimulation (tDCS) targeting the frontal eye field (FEF) and cerebellum using the Positive and Negative Affect Schedule (PANAS). Twenty-five healthy adults completed PANAS assessments after anodal and sham tDCS delivered in separate sessions. A repeated-measures general linear model evaluated stimulation type (anodal vs. sham), stimulation site (FEF vs. cerebellum), and time (pre- vs. post-stimulation). For positive affect, no significant interaction or main effects were observed across type, site, or time (all p > 0.05), with nonsignificant effects of site (p = 0.07) and stimulation type (p = 0.97). For negative affect, neither type (p = 0.11) nor site (p = 0.48) showed significant main effects; however, a significant three-way interaction among time, site, and type emerged (p = 0.01). Across all stimulation conditions, both positive and negative affect decreased post-stimulation. These findings indicate that tDCS targeting oculomotor regions does not produce adverse affective outcomes and is emotionally safe for experimental use. Future work should use extended stimulation protocols in clinical populations to further examine tDCS-related emotional modulation.