| Title: | Spatiotemporal dynamics of odor representations in the human brain revealed by EEG decoding |
| Author(s): | Kato M; Okumura T; Tsubo Y; Honda J; Sugiyama M; Touhara K; Okamoto M; |
| Address: | "Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan. College of Information Science and Engineering, Ritsumeikan University, Kusatsu, 525-8577, Japan. Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan. Graduate School of Frontier Sciences, the University of Tokyo, Kashiwa-shi, Chiba, 277-8561, Japan. International Research Center for Neurointelligence (WPI-IRCN), Institutes for Advanced Study, the University of Tokyo, Tokyo, 113-0033, Japan" |
| ISSN/ISBN: | 1091-6490 (Electronic) 0027-8424 (Print) 0027-8424 (Linking) |
| Abstract: | "How the human brain translates olfactory inputs into diverse perceptions, from pleasurable floral smells to sickening smells of decay, is one of the fundamental questions in olfaction. To examine how different aspects of olfactory perception emerge in space and time in the human brain, we performed time-resolved multivariate pattern analysis of scalp-recorded electroencephalogram responses to 10 perceptually diverse odors and associated the resulting decoding accuracies with perception and source activities. Mean decoding accuracies of odors exceeded the chance level 100 ms after odor onset and reached maxima at 350 ms. The result suggests that the neural representations of individual odors were maximally separated at 350 ms. Perceptual representations emerged following the decoding peak: unipolar unpleasantness (neutral to unpleasant) from 300 ms, and pleasantness (neutral to pleasant) and perceptual quality (applicability to verbal descriptors such as 'fruity' or 'flowery') from 500 ms after odor onset, with all these perceptual representations reaching their maxima after 600 ms. A source estimation showed that the areas representing the odor information, estimated based on the decoding accuracies, were localized in and around the primary and secondary olfactory areas at 100 to 350 ms after odor onset. Odor representations then expanded into larger areas associated with emotional, semantic, and memory processing, with the activities of these later areas being significantly associated with perception. These results suggest that initial odor information coded in the olfactory areas (<350 ms) evolves into their perceptual realizations (300 to >600 ms) through computations in widely distributed cortical regions, with different perceptual aspects having different spatiotemporal dynamics" |
| Keywords: | *Brain/physiology *Brain Mapping Electroencephalography Emotions Humans Memory *Odorants *Olfactory Perception Smell Eeg Mvpa emotion olfaction perception; |
| Notes: | "MedlineKato, Mugihiko Okumura, Toshiki Tsubo, Yasuhiro Honda, Junya Sugiyama, Masashi Touhara, Kazushige Okamoto, Masako eng Research Support, Non-U.S. Gov't 2022/05/19 Proc Natl Acad Sci U S A. 2022 May 24; 119(21):e2114966119. doi: 10.1073/pnas.2114966119. Epub 2022 May 18" |
