Modification of DIF summating potential components by stimulus biasing

Abstract

Positive and negative components of the summating potential (DIF SP) recorded with differential electrodes were studied in the presence of a low-frequency stimulus at different phases of this bias signal. Two clearly discernible ranges of behavior were observed depending on the sound-pressure level of the low-frequency stimulus. At the lower stimulus biasing levels, the SP components could be reversibly enhanced or depressed according to the magnitude (or equivalent magnitude at different phases) of the bias. At the higher intensity ranges, the SP output was generally depressed. The latter effect on the SP is a manifestation of the interference phenomenon.