Event Abstract Back to Event Duration of gamma-band activity depends on visual search difficulty: evidence from human intracerebral EEG recordings Tomas Ossandon1, 2*, P. Kahane3 and J P Lachaux1, 2 1 Inserm U821, Brain Dynamics and Cognition, France 2 Université Lyon 1, France 3 Dpto. Neurology Inserm U704, France The search for a singleton in an array of distractors generally increases in duration with the number of distractors (serial search), unless specific differences between singleton and distractors allow for the singleton to pop-out. Following recent suggestions that visual attention might be at least in part mediated by synchronization of neural activity in the gamma band ( > 40 Hz), we hypothetized that search displays should induce gamma band responses with durations dependant on the difficulty of the search, that is, on the number of distractors,in the case of serial search. We tested this hypothesis with direct recordings of neural activity in ten epileptic patients implanted with depth electrodes for therapeutic purposes. We used a classic search paradigm (search for a «T» in an array of «L») and measured the duration of gamma band responses induced by the display as a function of the number of distractors, in a number of regions including low- and high-level visual areas in the ventral and dorsal streams and frontal attentional areas. We found our prediction to be true in specific cortical sites in early visual areas and frontal regions. Those responses co-occurred with other gamma band responses, in which duration was not affected by the duration of the search. Our results demonstrate that the link between attention and gamma band synchronization should be qualified, and may depend on their site of emergence in the brain. Conference: 10th International Conference on Cognitive Neuroscience, Bodrum, Turkey, 1 Sep - 5 Sep, 2008. Presentation Type: Poster Presentation Topic: Brain Electrical Oscillations in Cognition Citation: Ossandon T, Kahane P and Lachaux J (2008). Duration of gamma-band activity depends on visual search difficulty: evidence from human intracerebral EEG recordings. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.131 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 Dec 2008; Published Online: 05 Dec 2008. * Correspondence: Tomas Ossandon, Inserm U821, Brain Dynamics and Cognition, Lyon, France, tossandon@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 Tomas Ossandon P. Kahane J P Lachaux Google Tomas Ossandon P. Kahane J P Lachaux Google Scholar Tomas Ossandon P. Kahane J P Lachaux PubMed Tomas Ossandon P. Kahane J P Lachaux 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.