DLPFC 1 adult 1 alertness 1 article 1 attentional deployment 1 controlled study 1 dorsolateral prefrontal cortex 1 electrodermal response 1 emotional reactivity 1 female 1 gaze 1 human 1 human experiment 1 major clinical study 1 photography 1 self-referential processing social-evaluative threat 1 tDCS 1 transcranial direct current stimulation 1