Auditory cortex neuronal tuning is sensitive to statistical structure of early acoustic environment

Abstract

Event Abstract Back to Event Auditory cortex neuronal tuning is sensitive to statistical structure of early acoustic environment Hania Koever1*, Yi-Ting L. Tseng1, Kirt Gill1 and Shaowen Bao1 1 University of California at Berkeley, United States Whereas sensory stimuli vary along a continuum, behavioral responses to these stimuli are discrete. The perceptual system can help translate sensory inputs into behaviors by parsing continuous stimuli into discrete perceptual categories. Some forms of categorical perception are innate and may reflect intrinsic characteristics of sensory processing; others, however, depend on learning and experience. In humans, for example, native English speakers perceive a distinct difference between the speech sounds /la/ and /ra/, whereas native Japanese speakers do not. Likewise, some species of songbirds categorically perceive note duration in a manner that depends on experience with their specific native song dialect. Despite evidence for experience-dependent categorical sound perception in a range of species from humans to rodents, it is not clear what rules neurons use to segment acoustic inputs into categories. Evidence from linguistics suggests that the statistical structure of acoustic inputs during an early stage of development affects categorical perception. For example, the distribution of speech sounds plays a role, with bimodal, but not unimodal distributions of speech sounds leading to categorical perception in infants. Additionally, infants are sensitive to the transitional probabilities between speech sounds, and perceptually group sounds that repeatedly occur together. To investigate the effect of the statistical structure of early acoustic inputs on neural tuning in auditory cortex, we exposed young rats (postnatal day (p)9 to p45) to sequences of pure tones that were grouped into two categories based on transitional probabilities alone. Pure tones were organized into one-second long sequences of six tones, in which all tones within a sequence were drawn from either a low frequency or high frequency category of tones. In this design, tones within a category had a high probability of occurring successively within a sequence (high transitional probability), whereas tones from different categories never occurred within a sequence (low transitional probability). We used extracellular recording in anaesthetized rats to map primary auditory cortex, and compared neural tuning in exposed rats to that of naïve rats, as well as rats exposed to control tone sequences with homogeneous statistics. Neurons in primary auditory cortex of the categorical sequence group differed from those in the naïve and control groups in terms of the shape of their frequency response tuning curves. In particular, neurons tuned to frequencies near category boundaries had steeper slopes at the category boundary. In addition, receptive fields exhibited a tendency to code for either the low or high category, rather than straddling two categories. In conclusion, neuronal tuning in primary auditory cortex is sensitive to the transitional probabilities of sounds encountered during an early period of development. We are currently performing behavioral experiments to determine whether the altered neuronal tuning has a perceptual correlate. Conference: Computational and Systems Neuroscience 2010, Salt Lake City, UT, United States, 25 Feb - 2 Mar, 2010. Presentation Type: Poster Presentation Topic: Poster session III Citation: Koever H, Tseng YL, Gill K and Bao S (2010). Auditory cortex neuronal tuning is sensitive to statistical structure of early acoustic environment. Front. Neurosci. Conference Abstract: Computational and Systems Neuroscience 2010. doi: 10.3389/conf.fnins.2010.03.00268 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: 05 Mar 2010; Published Online: 05 Mar 2010. * Correspondence: Hania Koever, University of California at Berkeley, Berkeley, United States, haniakoever@berkeley.edu 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 Hania Koever Yi-Ting L Tseng Kirt Gill Shaowen Bao Google Hania Koever Yi-Ting L Tseng Kirt Gill Shaowen Bao Google Scholar Hania Koever Yi-Ting L Tseng Kirt Gill Shaowen Bao PubMed Hania Koever Yi-Ting L Tseng Kirt Gill Shaowen Bao 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.