taVNS on Pupillary Response and Perceptual Learning

"taVNS will be delivered by Digitimer DS7 Constant Current Stimulator (an FDA cleared medical device intended for human nerve and muscle stimulation).~Stimulation is delivered via sticky pad electrodes all placed on the left side of the body (cymba concha, earlobe, and ulnar side of the wrist). Stimulation is delivered by a 3000ms pulse train (100us pulse width and 25Hz stimulation frequency). The current applied will be between 0.01uA to 9uA. The intervention will be delivered over the course of four sessions approximately one week apart."

"Sham stimulation will be delivered by Digitimer DS7 Constant Current Stimulator (an FDA cleared medical device intended for human nerve and muscle stimulation).~Stimulation is delivered via sticky pad electrodes all placed on the left side of the body (either earlobe or forearm)."