Feature-based attention at work: Neuronal oscillations signify top-down control during continous visual tracking and memory retention

Abstract

Event Abstract Back to Event Feature-based attention at work: Neuronal oscillations signify top-down control during continous visual tracking and memory retention Gernot G. Supp1*, J. F. Hipp1 and A.K Engel1 1 Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Germany One obvious need in everyday life of humans is to select visual information in a context-dependent, goal-directed manner. Attentional processes are of critical relevance to control the perception and memorization of visual features such as shape or motion. To investigate whether feature-specific attention is associated with changes of oscillatory neural activity, we performed a MEG-study using a continuous shape- and motion-tracking paradigm. Participants (n=25) fixated centrally while they were presented with a smoothly shaped blob that permanently changed its shape and position. The color of the fixation point cued the subject to continuously attend and memorize one of two visual features (either shape or motion). This feature-specific tracking interval was followed by a period of continued visual stimulation during which the subject had to memorize the respective object feature just tracked previously (retention interval). At the end of each trial the subjects indicated in a two-alternative forced choice regime, which shape or which motion had been perceived just before the color change of the fixation point. The transitions between intervals were designed to ensure a sustained attentional engagement of the subjects (flat hazard rate; mean condition duration: 4s). In total, our set-up yielded five experimental conditions that were solely defined by cued instructions, while physical stimulation was identical across all conditions: tracking of shape / motion, retention of shape / motion and one baseline condition (visual stimulation without a task). Magnetic brain signals were recorded using a 275-channel whole-head MEG system. The 2-(tasks)-by-2-(feature-types) design enabled us to analyze oscillatory brain responses on the basis of pairwise contrasts and conjunction analysis by means of spectral analysis and source localization (linear beamforming). We found that the visual stimulation profoundly increased gamma power (> 50 Hz) bilaterally in early visual brain regions along the entire time course of the trials (i.e. persistent gamma activity in the range of seconds). Importantly, the engagement in a given task directed to a particular feature was found to selectively increase gamma oscillations in specific brain areas. Whereas tracking of shape led to a bilateral gamma power increase in extrastriate occipital brain regions, motion tracking was associated with an increase of gamma power in left parietal (anterior IPS) and bilateral frontal (FEF) cortical areas. Retention of shape information yielded a weaker but similar gamma activation pattern as compared to tracking of the same feature. Similarly, retention of motion led to a left parietal and bilateral frontal gamma increase, comparable to the activation pattern during motion tracking. However, gamma activity during retention of motion was characterized by a significantly lower gamma power in extrastriate occipital cortices as compared to tracking. These results suggest that deployment of feature-based attention is reflected by a gamma power increase in distinct networks that involve, in a specific and context-dependent manner, extrastriate, parietal and frontal brain areas. 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: Supp GG, Hipp JF and Engel A (2008). Feature-based attention at work: Neuronal oscillations signify top-down control during continous visual tracking and memory retention. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.148 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: Gernot G Supp, Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Geneva, Germany, g.supp@uke.de 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 Gernot G Supp J. F Hipp A.K Engel Google Gernot G Supp J. F Hipp A.K Engel Google Scholar Gernot G Supp J. F Hipp A.K Engel PubMed Gernot G Supp J. F Hipp A.K Engel 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.