When one size does not fit all: Phenotypic bias in noninvasive neuromodulation

While individual variability in response to noninvasive brain stimulation approaches like transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) is common, it has been assumed that there are no systematic differences between large groups of people in either suitability for or responsiveness to these forms of neuromodulation. However, in recent years, phenotypic bias, or the tendency of devices to perform differently based on physical characteristics like hair type or skin tone, has emerged as a recognized problem across scalp-based neuroscience tools [1].