Successful long-term memory encoding relies on both engagement and disengagement of regions in an extended network

Abstract

Event Abstract Back to Event Successful long-term memory encoding relies on both engagement and disengagement of regions in an extended network Esther B. Meeuwissen1*, Atsuko Takashima1, Guillen Fernandez1 and Ole Jensen1 1 Donders Institute, Netherlands It has been debated to what extend working memory (WM) maintenance is required for long-term memory (LTM) encoding. While this question has been studied using fMRI, less is known about the electrophysiological network properties reflecting long-term memory formation. In this study we have investigated oscillatory activity reflecting encoding of sequential information in LTM using magnetoencephalography (MEG). Participants were asked to encode or maintain the order of three words per trial. All trials constituted the sequential presentation of 3 written words followed by a 3.4 s maintenance period. The experiment had 35 blocks which started with the encoding of 9 word-triplets in LTM. We advised subjects to make sentences of the three words to encode the order. Then, 6 WM trials followed. Finally, the word order of the 9 trials encoded in LTM had to be retrieved. Time-frequency analysis of power was performed for the data in the maintenance period and sources were identified using a DICSs beamformer. First we investigated the subsequent memory effect (SME) for the LTM trials during the maintenance period. Alpha activity (9-12 Hz) in occipital cortex and gamma activity (55-65 Hz) in left BA6 (SMA/ pre-SMA) were stronger for later remember compared to later forgotten sequences. Interestingly, the SME was much stronger in the alpha than the gamma band. When comparing LTM to WM trials we found a stronger gamma band effect at a similar location in left BA6. The posterior increase in alpha activity most likely reflects the disengagement of visual areas serving to allocate resources to other memory structures. The gamma activity in SMA/ pre-SMA is likely to reflect language processes (e.g. WM related phonological rehearsal) supporting the sequential encoding of the word list. These data demonstrate that successful LTM encoding relies on an extended network in which engagement and disengagement are reflected in the gamma and alpha band, respectively. Conference: Biomag 2010 - 17th International Conference on Biomagnetism , Dubrovnik, Croatia, 28 Mar - 1 Apr, 2010. Presentation Type: Poster Presentation Topic: Neurocognition and Functional Connectivity Citation: Meeuwissen EB, Takashima A, Fernandez G and Jensen O (2010). Successful long-term memory encoding relies on both engagement and disengagement of regions in an extended network. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00332 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: 06 Apr 2010; Published Online: 06 Apr 2010. * Correspondence: Esther B Meeuwissen, Donders Institute, Nijmegen, Netherlands, esther.meeuwissen@fcdonders.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 Esther B Meeuwissen Atsuko Takashima Guillen Fernandez Ole Jensen Google Esther B Meeuwissen Atsuko Takashima Guillen Fernandez Ole Jensen Google Scholar Esther B Meeuwissen Atsuko Takashima Guillen Fernandez Ole Jensen PubMed Esther B Meeuwissen Atsuko Takashima Guillen Fernandez Ole Jensen 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.