The Effect of Bilateral tDCS of the Dorsolateral Prefrontal Cortex on Processing of Emotional Visual Stimuli. A Pilot Study on the Moderating Role of Empathy

Literature has documented the involvement of the dorsolateral prefrontal cortex (DLPFC) in affect and emotional processing. Also, the DLPFC has been linked to empathic responses. In this pilot study, we investigated the moderating effect of individual differences in trait empathy on valence and arousal responses to emotional (positive, negative) and neutral visual stimuli while the DLPFC was bilaterally stimulated by using transcranial Direct Current Stimulation (tDCS). Thirteen participants joined this single- blinded, within-subjects study and were asked to come to the laboratory for a tDCS session once a week for three weeks. Before starting the first session, participants filled out the Interpersonal Reactivity Index (IRI) as a measure of trait empathy. After five minutes into the stimulation session, participants were shown a slideshow presenting sixty images and were asked to rate each image by scoring valence and arousal. The results showed significant interaction effects for the tDCS condition and the IRI subscales, highlighting a significant role of individual levels of empathy that influenced the effect of neuromodulation.