Basic operations in working memory: Contributions from functional imaging studies

Institute of Medical Psychology, Goethe University, Heinrich-Hoffmann-Strasse 10, D-60528 Frankfurt am Main, Germany.
Behavioural brain research (Impact Factor: 3.03). 12/2010; 214(2):172-9. DOI: 10.1016/j.bbr.2010.05.041
Source: PubMed


Working memory (WM) constitutes a fundamental aspect of human cognition. It refers to the ability to keep information active for further use, while allowing it to be prioritized, modified and protected from interference. Much research has addressed the storage function of WM, however, its 'working' aspect still remains underspecified. Many operations that work on the contents of WM do not appear specific to WM. The present review focuses on those operations that we consider "basic" because they operate in the service of memory itself, by providing its basic functionality of retaining information active, in a stable yet flexible way. Based on current process models of WM we review five strands of research: (1) mnemonic selection of one item amongst others, (2) updating the focus of attention with the selected item, (3) updating the content of visual WM with new item(s), (4) rehearsal of visuospatial information and (5) coping with interference. We discuss the neuronal substrates underlying those operations obtained with functional magnetic resonance imaging and relate them to findings on "executive functions". The presented data support the view that WM emerges from interactions between higher sensory, attentional and mnemonic functions, with separable neural bases. However, interference processing and the representation of rule switching in WM may demand an extension of the current WM models by executive control functions.

Download full-text


Available from: Christoph Bledowski
  • Source
    • "Specifically, theta band oscillations reflect the organization of sequentially ordered WM items (Schmiedt et al., 2005;Sauseng et al., 2009;Hsieh et al., 2011;Roberts et al., 2013;Roux and Uhlhaas, 2014) and alpha oscillations reflect inhibition of task-irrelevant information (Gevins and Smith, 2000;Jokisch and Jensen, 2007;Klimesch et al., 2007;Tuladhar et al., 2007;Manza et al., 2014). According to the " multiple-component model " by Baddeley and Hitch, unique central executive control mechanisms, such as item organization and inhibition of irrelevant information (Bledowski et al., 2010), are activated for different types of information in WM (Baddeley, 1992Baddeley, , 2010Baddeley, , 2012). We hypothesized that frontal theta would increase and posterior alpha would decrease as temporal WM load increased. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Temporal information can be retained and manipulated in working memory. Neural oscillatory changes in working memory were examined by varying temporal working memory load. Electroencephalography was obtained from 18 subjects performing a temporal version of the visual n-back working memory task (n = 1 or 2). Electroencephalography revealed that posterior alpha power decreased and temporal region-distributed beta power increased as working memory load increased. This result is consistent with previous findings that posterior alpha band reflects inhibition of task-irrelevant information. Furthermore, findings from this study suggest that temporal region-distributed beta band activity is engaged in the active maintenance of temporal duration in working memory.
    Full-text · Article · Jan 2016 · Frontiers in Psychology
  • Source
    • "Las funciones de control cognitivo y la memoria de trabajo subyacen a este interjuego de las funciones ejecutivas y de auto-regulación. Asimismo, las interacciones entre la selección mnémica y la focalización atencional, apoyadas por distintos substratos neuronales, podrían ser pre-requisitos básicos para la actualización del contenido de la memoria de trabajo (Cowan, 1988; Oberauer, 2002; Bledowski et al., 2010). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Una extensa literatura nos señala la importancia de las funciones ejecutivas y auto- regulación para el aprendizaje y desempeño. A pesar de las diferentes concepciones y modelos teóricos, ambos constructos se refieren a un conjunto de procesos cognitivos que hacen a la coordinación del procesamiento de la información y el control cognitivo. El presente capitulo presenta una conceptualización de estos procesos cognitivos en relación al desempeño escolar y otros constructos que han sido estudiados en la literatura. Además, este capítulo presenta resultados que señalan efectos del contexto y considera factores genéticos y epigenéticos e intervenciones, como así también presenta una discusión acerca de las condiciones de estos resultados y sus limitaciones.
    Full-text · Chapter · Jan 2015
  • Source
    • "Functional neuroimaging studies have found activations of the superior frontal sulcus, posterior cingulate cortex, precuneus, posterior parietal cortex, and dorsolateral prefrontal cortex (DLPFC) and it is likely that distinct brain regions are involved in the different types of operation. The DLPFC seems to be prevalently involved in selection operations (Bledowski et al., 2010). WM can be explored using delayed recognition or recall tasks. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Several studies have shown that transcranial direct current stimulation (tDCS) is able to enhance performances on verbal and visual working memory (WM) tasks. Available evidence points to the right dorsolateral prefrontal cortex (DLPFC) as a critical area in visual WM, but to date direct comparisons of the effects obtained by stimulating the left versus the right DLPFC in the same subject are lacking. Our aim was to determine whether tDCS over the right DLPFC can differently affect performance as compared with left DLPFC stimulation. Ten healthy subjects performed a memory-guided visuospatial task in three conditions: baseline, during anodal stimulation applied over the right and during anodal stimulation applied over the left DLPFC. All the subjects also underwent a sham stimulation as control. Our results show that only active stimulation over the right DLPFC is able to increase performance when compared to the other conditions. Our findings confirm the crucial role played by the right DLPFC in spatial WM tasks.
    Full-text · Article · Oct 2014 · Functional neurology
Show more