RT Journal Article
T1 Effects of load and maintenance duration on the time course of information encoding and retrieval in working memory: from perceptual analysis to post-categorization processes
A1 Pinal Fernández, Diego
A1 Zurrón Ocio, Montserrat
A1 Díaz Fernández, Fernando
K1 Event-related potentials
K1 Working memory
K1 Delayed match-to-sample
K1 Encoding
K1 Retrieval
K1 Memory load
K1 Maintenance duration
K1 eLORETA
AB Working memory (WM) involves three cognitive events: information encoding, maintenance, and retrieval; these are supported by brain activity in a network of frontal, parietal and temporal regions. Manipulation of WM load and duration of the maintenance period can modulate this activity. Although such modulations have been widely studied using the event-related potentials (ERP) technique, a precise description of the time course of brain activity during encoding and retrieval is still required. Here, we used this technique and principal component analysis to assess the time course of brain activity during encoding and retrieval in a delayed match to sample task. We also investigated the effects of memory load and duration of the maintenance period on ERP activity. Brain activity was similar during information encoding and retrieval and comprised six temporal factors, which closely matched the latency and scalp distribution of some ERP components: P1, N1, P2, N2, P300, and a slow wave. Changes in memory load modulated task performance and yielded variations in frontal lobe activation. Moreover, the P300 amplitude was smaller in the high than in the low load condition during encoding and retrieval. Conversely, the slow wave amplitude was higher in the high than in the low load condition during encoding, and the same was true for the N2 amplitude during retrieval. Thus, during encoding, memory load appears to modulate the processing resources for context updating and post-categorization processes, and during retrieval it modulates resources for stimulus classification and context updating. Besides, despite the lack of differences in task performance related to duration of the maintenance period, larger N2 amplitude and stronger activation of the left temporal lobe after long than after short maintenance periods were found during information retrieval. Thus, results regarding the duration of maintenance period were complex, and future work is required to test the time-based decay theory predictions
PB Frontiers Media
YR 2014
FD 2014
LK http://hdl.handle.net/10347/21379
UL http://hdl.handle.net/10347/21379
LA eng
NO Pinal D, Zurrón M and Díaz F (2014) Effects of load and maintenance duration on the time course of information encoding and retrieval in working memory: from perceptual analysis to post-categorization processes. Front. Hum. Neurosci. 8:165
NO This study was funded by the Spanish Government: Ministerios de Educación (BES 2008-005929) and Economía y Competitividad (PSI2010-22224-C03-03); and by the Galician Government: Consellería de Economía e Industria (10 PXIB 211070 PR), and Consellería de Educación e Ordenación Universitaria (Axudas para a Consolidación e Estruturación de unidades de investigación competitivas do sistema universitario de Galicia. Ref: CN 2012/033)
DS Minerva
RD 2 may 2026