Event Abstract Back to Event Stimulus expectation modulates sensory-driven responses to deviant stimuli Paul Briley1* and K. Krumbholz1 1 MRC Institute of Hearing Research, United Kingdom The auditory mismatch response (MR), which can be evoked by presenting infrequent deviant stimuli in a sequence of frequent standards, is traditionally thought to reflect the output of a change-detection mechanism, which actively monitors the incoming stimulus stream for regularities, forms an expectation of the next stimulus and elicits a response when the actual stimulus deviates from this expectation. According to this hypothesis, the neural generators of the MR are distinct from the generators of the sensory-driven response to the deviants. Recently, however, it has been suggested that the MR is based solely on stimulus-specific adaptation to the standard stimulus. In contrast to the putative change-detection mechanism, adaptation is a passive rather than an active process and inherently involves the sensory-driven response, rather than being distinct from it. The aim of the current study was to test this hypothesis by examining whether the MR to a deviant can be explained by the added adaptational effects of the preceding standards. For that, we measured the responses to probe stimuli that were preceded either by single or by multiple standards and estimated the adaptational effect of the standards in the multi-standard conditions using the probe responses from the single-standard conditions. We found that, when the probe stimulus was identical to the standards, its response could be fully accounted for by adaptation. However, when the probe was a deviant (i.e. differed from the standards), its response was considerably larger than predicted based on adaptation alone, suggesting the contribution of an additional, expectation-related mechanism. However, contrary to previous thinking, this expectation-related contribution to the deviant response seemed to reflect a modulation of the sensory-driven response to the deviants, rather than the output of distinct change-detection generators. A special baseline-correction procedure was applied to search for possible neural correlates of the executive mechanism responsible for mediating the observed expectation-related sensory modulation. This procedure revealed a sustained response which was active throughout each stimulus sequence and seemed to arise from a source outside of the classical (unimodal) auditory cortical areas. These findings suggest the existence of an expectation mechanism in the auditory system, which monitors the incoming stimulus stream and modulates sensory-driven responses to novel or infrequent events. This expectation mechanism would be assumed to play a crucial role in facilitating the auditory system’s early-warning function. Conference: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications, Budapest, Hungary, 4 Apr - 7 Apr, 2009. Presentation Type: Poster Presentation Topic: Poster Presentations Citation: Briley P and Krumbholz K (2009). Stimulus expectation modulates sensory-driven responses to deviant stimuli. Conference Abstract: MMN 09 Fifth Conference on Mismatch Negativity (MMN) and its Clinical and Scientific Applications. doi: 10.3389/conf.neuro.09.2009.05.100 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 26 Mar 2009; Published Online: 26 Mar 2009. * Correspondence: Paul Briley, MRC Institute of Hearing Research, Nottingham, United Kingdom, paul@ihr.mrc.ac.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Paul Briley K. Krumbholz Google Paul Briley K. Krumbholz Google Scholar Paul Briley K. Krumbholz PubMed Paul Briley K. Krumbholz Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.