Differential modulatory effects of transcranial direct current stimulation on a facial expression go-no-go task in males and females

The ability to recognize facial expressions has been shown to be different between males and females. Here we aimed to explore further this matter and investigate whether the effects of tDCS applied over the superior temporal cortex differs between males and females during a facial expression go-no-go task. Fourteen healthy subjects were exposed to a facial expression go-no-go task while they received two different conditions of stimulation: anodal tDCS of the left temporal cortex (with cathodal stimulation of the right temporal cortex) and sham tDCS. The order of conditions was randomized and counterbalanced across subjects. During each stimulation session (after 5 min of stimulation), subjects underwent a go-no-go task. The results showed that women had significantly more correct answers when compared to men (p = 0.03) that was independent of condition of stimulation and valence of figures. In addition, women made significantly less errors during temporal stimulation when compared to sham stimulation (p = 0.009) when responding to sad faces. Similarly, men made significantly more errors during temporal active stimulation as compared with sham stimulation (p = 0.004) when responding to sad faces. Our results confirmed the notion that performance to facial expression recognition is increased in females compared with males and that modulation of temporal cortex with tDCS leads to differential effects according to gender.