Spatial discrimination learning of electrocutaneous stimuli

The present study investigates whether the spatial discrimination of somatosensory stimuli can be improved with training when sets of 1, 2, 3, or 4 simultaneously stimulated electrodes (so called patterns) have to be discriminated. Healthy human subjects were trained over a period of 5 days to discriminate 23 different somatosensory stimulus patterns. Somatosensory stimulation was based on electrical stimuli applied through an array of eight electrodes attached with a cuff to the skin of the left upper arm. Daily sessions consisted of a pretest, a training phase, and a posttest. Pre- and posttests revealed subject's discrimination ability. Performance of a treatment group receiving sensory real training was compared to performance of a control group receiving sham training. Results revealed (1) improvements of discrimination ability in both groups, and (2) a significantly greater discrimination performance throughout the training period in the treatment group as compared to the control group. The present study demonstrates that discrimination of electrocutaneous stimuli can be improved through training. Results illustrate that electrocutaneous stimuli are a possible and easy-to-apply tool for biofeedback settings.