A review of computational models of transcranial electrical stimulation

Transcranial electrical stimulation (tES), which includes transcranial direct current stimulation (tDCS) and electroconvulsive therapy (ECT), has played an important role in the treatment of various psychiatric disorders. Decades of empirical research and clinical experience have led to new and improved brain stimulation techniques, but the mechanisms underlying treatment efficacy and side effects are poorly understood. As part of the ongoing research effort in tES, the value of computational models of transcranial electric current flow has been increasingly recognized, and a proliferation of modeling studies have been published. The complexity of these tES models ranges from simple sphere-based models of the head to high-resolution anatomical reconstructions based on head-image scans. This review provides an up-to-date description and comparison of existing computational models of tES (primarily tDCS and ECT), focusing on the modeling approaches adopted in previous studies and their significant finding.