Transcranial random noise stimulation and cognitive training improves face perception.

Abstract

Several studies have found that cognitive training can improve face recognition. However, the effects tend to be relatively small and short-lived. Recent research has found that non-invasive brain stimulation techniques such as transcranial random noise stimulation (tRNS) can enhance and extend the effects of cognitive training in other domains, but this has not been examined for face recognition. In this study, we examined whether tRNS modulated the effects of a face recognition training program in people with typical face recognition abilities. Participants completed a face discrimination training task for one hour per day over fi ve days. Training was preceded by twenty minutes of active high frequency tRNS or sham stimulation to lateral occipitotemporal cortices. Participants completed a battery of face processing tasks assessing face memory (the Cambridge Face Memory Test, CFMT), face perception (the Cambridge Face Perception Test, CFPT), and patterns of eye-movements to faces (free-viewing of faces and social scenes); these took place before training, after training, and at a one-week follow-up session. Participants who received active stimulation showed signifi cant improvement on the CFPT following training, whereas those who received sham stimulation did not show any training gains. There was no improvement for inverted faces, and neither the active or sham stimulation group showed an improvement on the CFMT, or any change in eye-movement patterns. These results suggest that tRNS can enhance the effectiveness of face recognition training programmes, but further work is needed to establish whether perceptual gains can be generalised to memory.