Abstract #116: Simulations of Temporal Interference Tcs in a Realistic Head Model

Introduction: Positive effects of transcranial current stimulation (tCS) have been demonstrated. However, standard applications produce nonfocal and superficial peak electric fields. Directly stimulating deep areas is possible (Huang et al., 2017), but not without stimulating overlying regions as well. Recently, temporal interference tCS (TI-tCS) was proposed to overcome these problems (Grossman et al., 2017): two electric fields are imposed by current injection with two stimulators at frequencies chosen such that neurons do not respond to each separately (e.g. 2000 and 2010 Hz), but do respond to the envelope of the amplitude-modulated field at the difference frequency. In a given location, effect size depends on the angle between fields and amplitude of the smallest field. Theoretically, this could produce an effect in deep areas while not stimulating overlying areas, and changing the ratio between the input currents could be used to steer the peak field location. This concept has been demonstrated in a cylindrical model and with rodent experiments [2]. Here, we present simulations of TI-tCS in a realistic human head model to test whether this technique can be used for deep and/or more focal stimulation.