Event Abstract Back to Event Neuronal synchronization during saccade planning to tactile targets Verena N. Buchholz1*, Ole Jensen1 and Pieter W. Medendorp1 1 Radboud University, Donders Institute for Brain, Cognition and Behaviour, Netherlands Both single-unit studies in macaques and neuroimaging studies in humans indicate that the posterior parietal cortex (PPC) is involved in spatial processing and sensory-guided actions, such as saccades. Recently, using magnetoencephalography (MEG), we identified the spectral signature of the human PPC during saccade planning to remembered visual targets, showing gaze-centered directional-selective power modulations in alpha (8-12 Hz) and gamma (70-100 Hz) bands. Here we studied the reference frame transformations in parietal cortex while planning and making saccades to remembered tactile targets. Behavioral studies in this domain indicate that tactile stimuli can evoke reflexive saccades, suggesting an instantaneous transformation from the somatotopic representation in early somatosensory areas to a gaze-centered oculomotor representation in PPC. We recorded ongoing magnetoencephalographic signals to investigate the fast temporal aspects of human somatosensory and parietal activity in this transformation process. In the experiment, subjects had to fixate either to the left or right of the body midline, while a tactile stimulus was applied to an invisible fingertip located either to the left or right of the fixation point. We examined changes in spectral power during the delay period, excluding error trials based on EOG eye tracking. After presentation of the target, gamma band activity (65-95Hz) transiently increased and beta band activity decreased in the somatosensory areas contralateral to the stimulated hand (somatotopic lateralization). At parietal sensors however, we found a different pattern of lateralization. The lateralization of gamma band activity now depended on the remembered location of the tactile target relative to the current fixation point. Also alpha band lateralization depended on these oculomotor coordinates. Taken with previous results, these findings suggest that gamma band synchronization in the PPC reflects a mechanism to encode locations of targets for saccades relative to current gaze, irrespective of the sensory input modality. Furthermore, beta band showed a somatotopic lateralization, whereas alpha band showed gaze-centered, directional-selective increases of power at posterior sensors, consistent with a mechanism that functionally inhibits the areas that are disengaged during the oculomotor processing. 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: Buchholz VN, Jensen O and Medendorp PW (2010). Neuronal synchronization during saccade planning to tactile targets. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00164 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: 26 Mar 2010; Published Online: 26 Mar 2010. * Correspondence: Verena N Buchholz, Radboud University, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands, verena.buchholz@donders.ru.nl 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 Verena N Buchholz Ole Jensen Pieter W Medendorp Google Verena N Buchholz Ole Jensen Pieter W Medendorp Google Scholar Verena N Buchholz Ole Jensen Pieter W Medendorp PubMed Verena N Buchholz Ole Jensen Pieter W Medendorp 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.