Can transcranial electrical stimulation motor threshold estimate individualized tDCS doses over the prefrontal cortex? Evidence from reverse-calculation electric field modeling

We recently conducted a study examining whether transcranial electrical stimulation (TES) motor threshold (MT), reverse-calculation transcranial direct current stimulation (tDCS) electric field modeling, or both could potentially be used as methods of individualizing tDCS doses(1). We found that TES MT significantly correlates with a reverse-calculated tDCS dosage in the motor cortex and were intrigued by the possibility of using TES MT as an MRI-free method of individually dosing tDCS(1). A limitation of this previous work was that we did not test the utility of TES MT to estimate reverse-calculation tDCS doses outside of the motor cortex.