Decoding subjective simultaneity from neuromagnetic signals

Abstract

Event Abstract Back to Event Decoding subjective simultaneity from neuromagnetic signals Kohske Takahashi1*, Shohei Hidaka2 and Katsumi Watanabe3, 4, 5 1 The University of Tokyo, Japan 2 Indiana University, Department of Psychological and Brain Sciences, United States 3 National Institute of Advanced Industrial Science and Technology, Japan 4 Japan Science and Technology Agency, Japan 5 National Center for Child Health and Development, Japan The present study examined neural correlate of subjective simultaneity by using whole-head magnetoencephalography. Nine participants performed an audiovisual simultaneity judgment task in the 160-channel MEG scanner (YOKOGAWA Corp.). The auditory and visual stimuli were presented with 5 stimulus onset asynchronies (SOA; 0, ±90, ±180 ms), and the participants were asked to judge whether the auditory and visual stimuli occurred simultaneously. The behavioral data showed that in the case of –90-ms-SOA (visual stimulus before auditory stimulus: VA) and +90-ms-SOA (visual stimulus after auditory stimulus: AV), subjective judgment varied (“simultaneous” response of VA and AV conditions were 59% and 65 %, respectively). In the MEG analysis, we chose 6 channels showing visual evoked activity for –90-ms-SOA, and also 6 channels showing auditory evoked activity for +90-ms-SOA. Then, we applied a wavelet analysis to the neuromagnetic signal recorded at each channel. In the classification test, we used a limited range of time–frequency component of the wavelet analysis (0 - 150 ms after the onset of the first stimulus; 8 Hz – 64 Hz), and compressed the components to 12 dimensions using principal component analysis. Subjective simultaneity was successfully classified, irrespective of which sensory modality was stimulated first. That is, classification trained with the VA data was able to decode the AV data, vice versa, at the rate better than chance. These results suggested that (1) simultaneity can be decoded by using MEG signals related to the sensory area; (2) the neural activity for the first stimulus, rather than the second stimulus, may predict subjective simultaneity; and (3) the neural activity reflecting subjective simultaneity is common among different sensory modalities. Conference: Biomag 2010 - 17th International Conference on Biomagnetism , Dubrovnik, Croatia, 28 Mar - 1 Apr, 2010. Presentation Type: Poster Presentation Topic: Sensory Processing and Functional Connectivity Citation: Takahashi K, Hidaka S and Watanabe K (2010). Decoding subjective simultaneity from neuromagnetic signals. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00232 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: 31 Mar 2010; Published Online: 31 Mar 2010. * Correspondence: Kohske Takahashi, The University of Tokyo, Tokyo, Japan, takahashi.kohske@gmail.com 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 Kohske Takahashi Shohei Hidaka Katsumi Watanabe Google Kohske Takahashi Shohei Hidaka Katsumi Watanabe Google Scholar Kohske Takahashi Shohei Hidaka Katsumi Watanabe PubMed Kohske Takahashi Shohei Hidaka Katsumi Watanabe 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.