Contextual Effects in Neuronal Responses to Complex Sounds Differ between Areas AI and AAF

Abstract

Event Abstract Back to Event Contextual Effects in Neuronal Responses to Complex Sounds Differ between Areas AI and AAF The primary auditory cortex (AI) and anterior auditory field (AAF) are both “core” auditory cortical areas that receive direct thalamic input. When stimulated with complex dynamic sounds, neurons in mouse AI and AAF exhibit different linear filtering properties as assessed through analysis of spectrotemporal receptive fields (STRFs) (Linden et al., J Neurophysiol 90:2660, 2003). Generally, AI filters are slower, and more broadly tuned, than those in AAF. We have recently proposed a new way to characterise auditory cortical response properties (Ahrens et al., J Neurosci 28:1929, 2008) with models that incorporate the nonlinear effects of short-term acoustic context. We used a variant of this “context model” to study responses in AI and AAF. This new model identified an inseparable “contextual reweighting field” (CRF) for each cell, which described how the efficacy of spectrotemporal elements within the stimulus was modulated by elements nearby in time and frequency, before integration by the STRF. Many contextual effects, including phenomena previously probed only with simple stimuli (such as forward suppression and combination sensitivity) can be captured within the response to a complex acoustic stimulus by this inseparable context model. We found that CRFs in both AI and AAF were typically inseparable; the predictive power of the inseparable context model was higher than that previously reported for separable context models by Ahrens et al., 2008, and substantially higher than that of linear STRF models. Moreover, in both AI and AAF, the effects of the CRF could be decomposed into a generally facilitatory, and often asymmetric, interaction between different frequencies present simultaneously, and a generally suppressive interaction between similar frequencies at different times. However, CRFs in AI and AAF differed in other respects: (1) CRF modulation was greater in AI than AAF; and (2) contextual effects in AI were slower and longer-lasting than those in AAF. These results indicate that neurons in both AI and AAF are sensitive to combinations of simultaneous tones, and that contextual interactions between sequential tones differ between AI and AAF. In combination with previous results, our new study suggests that AAF may be specialised for rapid, temporally precise processing, while AI neurons integrate more broadly along the temporal dimension. More generally, the CRF analysis demonstrates that nonlinear effects of acoustic context play a substantial role in shaping the responses of neurons in core auditory cortical areas. Conference: Computational and systems neuroscience 2009, Salt Lake City, UT, United States, 26 Feb - 3 Mar, 2009. Presentation Type: Poster Presentation Topic: Poster Presentations Citation: (2009). Contextual Effects in Neuronal Responses to Complex Sounds Differ between Areas AI and AAF. Front. Syst. Neurosci. Conference Abstract: Computational and systems neuroscience 2009. doi: 10.3389/conf.neuro.06.2009.03.135 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: 02 Feb 2009; Published Online: 02 Feb 2009. 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 Google Google Scholar PubMed 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.