title: Selective processing of auditory evoked responses with iterative-randomized stimulation and averaging: A strategy for evaluating the time-invariant assumption.
abstract: The recording of auditory evoked potentials (AEPs) at fast rates allows the study of neural adaptation, improves accuracy in estimating hearing threshold and may help diagnosing certain pathologies. Stimulation sequences used to record AEPs at fast rates require to be designed with a certain jitter, i.e., not periodical. Some authors believe that stimuli from wide-jittered sequences may evoke auditory responses of different morphology, and therefore, the time-invariant assumption would not be accomplished. This paper describes a methodology that can be used to analyze the time-invariant assumption in jittered stimulation sequences. The proposed method [Split-IRSA] is based on an extended version of the iterative randomized stimulation and averaging (IRSA) technique, including selective processing of sweeps according to a predefined criterion. The fundamentals, the mathematical basis and relevant implementation guidelines of this technique are presented in this paper. The results of this study show that Split-IRSA presents an adequate performance and that both fast and slow mechanisms of adaptation influence the evoked-response morphology, thus both mechanisms should be considered when time-invariance is assumed. The significance of these findings is discussed.
authors.affiliation: National Acoustic Laboratories, Australian Hearing Hub, 16 University Avenue, Macquarie University, NSW 2109, Sydney, Australia. Electronic address: joaquin.valderrama@nal.gov.au.
authors.forename: Joaquin T
authors.initials: JT
authors.lastname: Valderrama
authors.affiliation: Department of Signal Theory, Telematics and Communications, CITIC-UGR, University of Granada, C/ Periodista Daniel Saucedo Aranda s/n, Granada 18071, Spain. Electronic address: atv@ugr.es.
authors.forename: Angel
authors.initials: A
authors.lastname: de la Torre
authors.affiliation: Department of Signal Theory, Telematics and Communications, CITIC-UGR, University of Granada, C/ Periodista Daniel Saucedo Aranda s/n, Granada 18071, Spain. Electronic address: cmedina@ugr.es.
authors.forename: Carlos
authors.initials: C
authors.lastname: Medina
authors.affiliation: Department of Signal Theory, Telematics and Communications, CITIC-UGR, University of Granada, C/ Periodista Daniel Saucedo Aranda s/n, Granada 18071, Spain. Electronic address: segura@ugr.es.
authors.forename: Jose C
authors.initials: JC
authors.lastname: Segura
authors.affiliation: MRC Institute of Hearing Research, Royal South Hants Hospital, Southampton SO14 OYG, United Kingdom. Electronic address: ardt@soton.ac.uk.
authors.forename: A Roger D
authors.initials: ARD
authors.lastname: Thornton
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000162:Acoustics; D000328:Adult; D000465:Algorithms; D001303:Auditory Cortex / Q000502:physiology*; D001306:Auditory Pathways / Q000502:physiology; D001309:Auditory Threshold; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods*; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted; D013018:Sound Spectrography; D013997:Time Factors; D055815:Young Adult
keywords: ABR; Deconvolution; Evoked potentials; Jitter; MLR; Randomized stimulation and averaging (RSA); SOA; Time-invariant