Transcranial electrical stimulation has greatly developed as a new non-invasive neuromodulation technique in recent years. Previous tES simulations have rarely considered the frequency domain features of brain tissue parameters. The errors introduced into the cortical electric field distribution by frequency variations are quantified in this paper. The analysis is based on the enhanced five-layer realistic head model for two types of electrode topologies in the wide frequency domain. Two evaluation indexes are proposed to describe the cortical electric field distribution. The skull layer plays a dominant role in frequency-dependent errors, and the higher the frequency, the larger the errors. HD-tES electrode topology has better robustness than normal two-electrode topology. Frequency-dependent errors can advise the application of tES doses to produce better stimulation effects.

error analysis,electric field distribution,frequency domain features,transcranial electrical stimulation