title: Functional dissociation between regularity encoding and deviance detection along the auditory hierarchy.
abstract: Auditory deviance detection based on regularity encoding appears as one of the basic functional properties of the auditory system. It has traditionally been assessed with the mismatch negativity (MMN) long-latency component of the auditory evoked potential (AEP). Recent studies have found earlier correlates of deviance detection based on regularity encoding. They occur in humans in the first 50 ms after sound onset, at the level of the middle-latency response of the AEP, and parallel findings of stimulus-specific adaptation observed in animal studies. However, the functional relationship between these different levels of regularity encoding and deviance detection along the auditory hierarchy has not yet been clarified. Here we addressed this issue by examining deviant-related responses at different levels of the auditory hierarchy to stimulus changes varying in their degree of deviation regarding the spatial location of a repeated standard stimulus. Auditory stimuli were presented randomly from five loudspeakers at azimuthal angles of 0°, 12°, 24°, 36° and 48° during oddball and reversed-oddball conditions. Middle-latency responses and MMN were measured. Our results revealed that middle-latency responses were sensitive to deviance but not the degree of deviation, whereas the MMN amplitude increased as a function of deviance magnitude. These findings indicated that acoustic regularity can be encoded at the level of the middle-latency response but that it takes a higher step in the auditory hierarchy for deviance magnitude to be encoded, thus providing a functional dissociation between regularity encoding and deviance detection along the auditory hierarchy.
authors.affiliation: Institute for Brain Cognition and Behavior (IR3C), University of Barcelona, Passeig de la vall d'Hebron 171, 08035, Barcelona, Catalonia, Spain.|Brainlab - Cognitive Neuroscience Research Group, Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Catalonia, Spain.|Department of Audiology, Faculty of Rehabilitation Sciences, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Aghamolaei
authors.affiliation: Institute for Brain Cognition and Behavior (IR3C), University of Barcelona, Passeig de la vall d'Hebron 171, 08035, Barcelona, Catalonia, Spain.|Brainlab - Cognitive Neuroscience Research Group, Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Catalonia, Spain.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Zarnowiec
authors.affiliation: Institute for Brain Cognition and Behavior (IR3C), University of Barcelona, Passeig de la vall d'Hebron 171, 08035, Barcelona, Catalonia, Spain.|Brainlab - Cognitive Neuroscience Research Group, Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Catalonia, Spain.|Cognitive and Biological Psychology, Institute of Psychology, University of Leipzig, Leipzig, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Grimm
authors.affiliation: Institute for Brain Cognition and Behavior (IR3C), University of Barcelona, Passeig de la vall d'Hebron 171, 08035, Barcelona, Catalonia, Spain.|Brainlab - Cognitive Neuroscience Research Group, Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Catalonia, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Escera
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: auditory evoked potential; deviance magnitude; human; middle-latency response; mismatch negativity