Effects of transcranial electrical stimulation on face identification and related perceptual processes: a systematic...

Face identification is a core capacity underpinning effective social interaction and communication. Although a growing body of literature has examined the effects of transcranial electrical stimulation (TES) on face identification, findings remain fragmented and lack an integrative synthesis. This systematic review adopted a broad scope, encompassing all published studies on TES and face identification, with the aim of mapping methodological trends and substantive findings, rather than focusing on a specific subtype of intervention or population. We conducted a PRISMA-guided systematic review of TES effects on face identification. From an initial pool of 261 records, 28 studies met the eligibility criteria. Overall, the evidence highlights both the potential and the complexity of using TES to modulate face identification processing. Targeted stimulation of occipital and fusiform regions shows promising effects in some paradigms; however, inconsistent results and notable methodological limitations preclude definitive conclusions. In particular, small, demographically homogeneous samples limit generalizability, while heterogeneity in stimulation parameters, task designs, and outcome measures complicate cross-study comparisons. By underscoring the need for rigorously controlled experiments with greater anatomical precision, especially in clinical populations, this review aims to inform the development of more robust, transparent methodological guidelines and to support future investigations with stronger scientific relevance.