24-channel transcutaneous electrical sensory stimulation of the forearm: Effects on cognitive performance and autonomic arousal compared with single-electrode stimulation

Abstract

We sought to establish the effects on cognitive performance and auto-nomic arousal of a multi-electrode transcutaneous electrical sensory stimulator compared with single-electrode stimulation. Progressing from a feasibility study (n = 10) to a repeated-measures, within-subject study (n = 67), healthy, right-handed participants (34 male, mean age 28 ± 11.5 yrs.) received four separate predictable (" lines " or " ring ") or unpredictable (" fly " or " random ") complex electrical stimulation patterns to the non-dominant forearm via 24 individually program-mable electrodes, or single-electrode stimulation. During stimulation, participants in the main study performed a series of cognitively demanding tests or a two-point discrimination task and had their autonomic arousal (skin conductance response) monitored. Single-electrode " first felt " current intensity decreased from distal to proximal forearm, was positively correlated with forearm circumference and was lower in females. Single-electrode stimulation was associated with a significant de-cline in two-point discrimination performance. There were no significant autonomic