Perceptual interactions between electrocutaneous loudness and pitch

The effect of dimensional interaction was investigated for the perceptual dimensions of electrocutaneous pitch and loudness. Stimuli were delivered transcutaneously through a concentric bipolar electrode positioned above a cutaneous nerve bundle. Subjects classified stimuli as "high" or "low" the basis of perceived intensity or frequency. Classification reaction times were measured for stimuli differing on one dimension alone (baseline), on two correlated dimensions (correlation), or on two dimensions, each varying randomly (filtering). Interactions were manifested when, compared to baseline (RT=453 ms), reaction times were slower in the filtering condition (RT=472 ms) and faster in the correlation condition (RT=418 ms). This interaction effect is a potentially important consideration for the design of efficient sensory feedback schemes employing electrocutaneous stimulation.