The effect of visual and audiovisual competition on the auditory N1-P2 evoked potential.

BACKGROUND Use of a competition stimuli (e.g., video) in clinical settings is a widespread practice, yet the effects of these stimuli on evoked potentials are not well understood. PURPOSE The present investigation acquired the click evoked auditory N1-P2 in quiet and in two types of competition: during presentation of an unrelated visual stimulus or audiovisual stimulus. Responses were acquired in each of these conditions at two click stimulus levels (i.e., 35 and 65 dBnHL) to determine if the effect of competition was greater closer to threshold. An attempt was made to quantify effect robustness by examining within- and between-session reliability. RESEARCH DESIGN Repeated measures ANOVA. STUDY SAMPLE 17 normal hearing female subjects. RESULTS Findings indicated a significant effect of audiovisual competition on the amplitude of the N1-P2, and a borderline significant effect of visual competition on this index. The extent of visual competition was better conveyed when examined on a case-by-case basis, in which was revealed a subgroup of the sample that was negatively affected by visual competition. There was no interaction between competition and click stimulus level. CONCLUSIONS Although competition stimuli can negatively affect the amplitude of the N1-P2, consideration should be given to subjects on a case-by-case basis to warrant if removal of this stimulus is necessary.