ERP effects of load and item similarity on short-term recognition

Abstract

Event Abstract Back to Event ERP effects of load and item similarity on short-term recognition Christoph Bledowski1*, K. Spira1, Jochen Kaiser1 and B. Rahm1 1 Institute of Medical Psychology, Goethe-University, Germany During short-term memory recognition, higher memory load is thought to increase the amount of information to be searched, whereas higher target-probe similarity requires participants to match items more precisely. We included both factors in an event-related potential (ERP) study to test whether these two manipulations tap similar or different resources. In a delayed match-to-sample task 1 or 3 colours had to be encoded and maintained, and a single probe was presented which either matched, was similar to or was dissimilar to the learned colour(s). Behavioural results showed that both high load and high similarity increase recognition difficulty. Moreover, while load had no effect on dissimilar recognition, accuracy and response times were increased both for similar lures and matches under high load. The ERP analysis revealed a pronounced load effect widely distributed over the scalp which started already at about 100 ms post-stimulus onset and lasted for 700 ms. An effect of item-probe similarity was present between 200-800 ms over medial-central and lateral-frontal and -temporal electrode sites. Significant memory load × similarity interaction was observed between 200-500 ms post-probe. Specifically, over medial-central and lateral-temporal sites load effects differentiated between the three probe types peaking at 324, 380 and 478 ms for match, dissimilar and similar, respectively. Modelling the ERP-source activity identified the inferior frontal and temporal cortex as main contributors of the scalp ERP effects. These results suggest that load and item-similarity differentially affected the neuronal processes: the observed global amplitude reduction under high load may reflect an increase of global processing resources, whereas high item-similarity may more specifically impact neuronal responses related to memory matching as evident in the different time courses of processing matches, similar and dissimilar lures. Conference: 10th International Conference on Cognitive Neuroscience, Bodrum, Turkey, 1 Sep - 5 Sep, 2008. Presentation Type: Poster Presentation Topic: Memory & Learning Citation: Bledowski C, Spira K, Kaiser J and Rahm B (2008). ERP effects of load and item similarity on short-term recognition. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.263 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: 09 Dec 2008; Published Online: 09 Dec 2008. * Correspondence: Christoph Bledowski, Institute of Medical Psychology, Goethe-University, Frankfurt am Main, Germany, Germany.bledowski@em.uni-frankfurt.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 Christoph Bledowski K. Spira Jochen Kaiser B. Rahm Google Christoph Bledowski K. Spira Jochen Kaiser B. Rahm Google Scholar Christoph Bledowski K. Spira Jochen Kaiser B. Rahm PubMed Christoph Bledowski K. Spira Jochen Kaiser B. Rahm 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.