title: Thalamic and parietal brain morphology predicts auditory category learning.
abstract: Auditory categorization is a vital skill involving the attribution of meaning to acoustic events, engaging domain-specific (i.e., auditory) as well as domain-general (e.g., executive) brain networks. A listener's ability to categorize novel acoustic stimuli should therefore depend on both, with the domain-general network being particularly relevant for adaptively changing listening strategies and directing attention to relevant acoustic cues. Here we assessed adaptive listening behavior, using complex acoustic stimuli with an initially salient (but later degraded) spectral cue and a secondary, duration cue that remained nondegraded. We employed voxel-based morphometry (VBM) to identify cortical and subcortical brain structures whose individual neuroanatomy predicted task performance and the ability to optimally switch to making use of temporal cues after spectral degradation. Behavioral listening strategies were assessed by logistic regression and revealed mainly strategy switches in the expected direction, with considerable individual differences. Gray-matter probability in the left inferior parietal lobule (BA 40) and left precentral gyrus was predictive of "optimal" strategy switch, while gray-matter probability in thalamic areas, comprising the medial geniculate body, co-varied with overall performance. Taken together, our findings suggest that successful auditory categorization relies on domain-specific neural circuits in the ascending auditory pathway, while adaptive listening behavior depends more on brain structure in parietal cortex, enabling the (re)direction of attention to salient stimulus properties.
authors.affiliation: Max Planck Research Group "Auditory Cognition", Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany. Electronic address: mscharinger@cbs.mpg.de.
authors.forename: Mathias
authors.initials: M
authors.lastname: Scharinger
authors.affiliation: Max Planck Research Group "Auditory Cognition", Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Molly J
authors.initials: MJ
authors.lastname: Henry
authors.affiliation: Max Planck Research Group "Auditory Cognition", Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Erb
authors.affiliation: Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Meyer
authors.affiliation: Max Planck Research Group "Auditory Cognition", Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors.forename: Jonas
authors.initials: J
authors.lastname: Obleser
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001306:Auditory Pathways / Q000033:anatomy & histology; D001307:Auditory Perception; D003463:Cues; D003657:Decision Making; D005260:Female; D005829:Geniculate Bodies / Q000033:anatomy & histology; D006801:Humans; D007858:Learning; D016015:Logistic Models; D008297:Male; D036421:Nerve Fibers, Unmyelinated; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000033:anatomy & histology*; D013647:Task Performance and Analysis; D013788:Thalamus / Q000033:anatomy & histology*; D013997:Time Factors; D055815:Young Adult
keywords: Acoustic cues; Auditory categorization; Auditory thalamus; Cue utilization; Parietal cortex; Voxel-based morphometry