Selective processing of auditory evoked responses with iterative-1 randomized stimulation and averaging: A strategy for evaluating the time-2 invariant assumption.

Abstract

The recording of auditory evoked potentials (AEPs) at fast rates allows the study 22 of neural adaptation, improves accuracy in estimating hearing threshold and may 23 help diagnosing certain pathologies. Stimulation sequences used to record AEPs 24 at fast rates require to be designed with a certain jitter, i.e., not periodical. Some 25 authors believe that stimuli from wide-jittered sequences may evoke auditory 26 responses of different morphology, and therefore, the time-invariant assumption 27 would not be accomplished. This paper describes a methodology that can be 28 used to analyze the time-invariant assumption in jittered stimulation sequences. 29 The proposed method [Split-IRSA] is based on an extended version of the 30 iterative randomized stimulation and averaging (IRSA) technique, including 31 selective processing of sweeps according to a predefined criterion. The 32 fundamentals, the mathematical basis and relevant implementation guidelines of 33 this technique are presented in this paper. The results of this study show that 34 Split-IRSA presents an adequate performance and that both fast and slow 35 mechanisms of adaptation influence the evoked-response morphology, thus both 36 mechanisms should be considered when time-invariance is assumed. The 37 significance of these findings is discussed.