Effectiveness of invariant versus varied-color/varied-pattern visual alerting tasks during acquisition of late auditory evoked potentials

Abstract

Instructions for late auditory evoked potential (LAEP) testing include a need for the participant to remain alert. Previous studies show an inverse relationship between alertness level and waveform morphology. Thus, a need exists to maintain alertness during LAEP testing. If not maintained, a wide range of alertness, and thus waveform morphology, may exist from one run to the next. Therefore, if alertness level is not controlled, any variations in waveform morphology may be due to variations in alertness rather than auditory system integrity. Previous investigators have implemented visual tasks consisting of still or action images. In these tasks, a participant is typically instructed to attend to a video during LAEP testing. This project investigated the effectiveness of two visual alerting tasks: invariant blue with no pattern, versus varied colors/patterns occurring in 1-3 second random intervals. LAEPs were gathered on twenty-five young adult participants who were instructed to attend to a display of one of the screens. Six replicates were obtained for each screen in counter-balanced order. Results showed no significant (p>.05) differences in overall mean P1 or P2 latency or amplitude for the two screens. However, there was a significant difference between the two alerting tasks when examined across replicates.