Effect of transcranial direct current stimulation on emotional face perception over brain right dorsolateral prefrontal cortex in college students

Objective To investigate whether modulating the activation of dorsolateral prefrontal cortex(DLPFC) by transcranial direct current stimulation(tDCS) can influence emotional perception. Methods Seventy-eight undergraduates were randomly divided into four groups by simple random sampling method.TDCS (1.5 mA) noninvasive technique was used to test group 1 (n=23) for 3 minutes to intervene in DLPFC, group 2 (n=17) for 15 minutes to intervene in DLPFC, group 3 (n=20) for 3 minutes to intervene in primary visual cortex, and group 4 (n=18) for non-emotional picture test.The data were analyzed with repeated measurement variance analysis. Results (1) The interaction between short-term(3 min) stimulation of tDCS and facial expression was statistically significant (F(1, 22)=7.448, P=0.012). There was significant difference in positive face perception (before: 70.58%, period: 74.75%, P=0.036) and no significant difference in negative face perception (before: 70.58%, period: 70.73%, P=0.569). (2) There was no significant difference in the correlation between prolonged tDCS stimulation(15 min) and face expression recognition (F(1, 16)=1.621, P=0.221). (3) The primary visual cortex was not affected by anodal tDCS (F(1, 19) 0.05). (4) There was no significant difference in the interaction between tDCS and facial expression (F(1, 17)=2.566, P=0.128) when visual stimulus was changed to non-expressive faces. Conclusions By applying tDCS technique, the present findings suggest that modulating DLPFC can influence emotional face perception, and support the valence-specific lateralization of emotional perception. Key words: Dorsolateral prefrontal cortex; Transcranial direct current stimulation, anode; Emotional perception; Face detection