Article

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: 3.22). 12/2010; 214(2):172-9. DOI: 10.1016/j.bbr.2010.05.041
Source: PubMed

ABSTRACT 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.

0 Bookmarks
 · 
175 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: This ERP study used electrophysiological technique to examine how individual differences in the speed of working memory updating influence the use of syntactic and semantic information during on-line sentence argument interpretation, and the time course of that working memory updating effect. The basic structure of the experimental sentences was "Noun + Verb + adverb + 'le' + a two-character word", with the Noun being the sentence initial argument. This initial argument is animate or inanimate and the following verb disambiguates it as an agent or patient. The results at the initial argument revealed that, the quick-updating group elicited a larger positivity over the frontal cortex (within 500-800 ms post-noun onset) as compared with the slow-updating group. At the following disambiguating verb, the slow-updating group only showed a word order effect, indicating that the patient-first condition elicited a larger P600 (within 500-1,000 ms post-verb onset) than the agent-first one; for the quick-updating group, at the early stage of processing, the patient-first sentences elicited a larger N400 (within 300-500 ms post-verb onset) than the agent-first ones only when the initial argument was inanimate; however, at the late stage, the patient-first sentences elicited an enhanced P600 (within 800-1,000 ms post-verb onset) only when the initial argument was animate. These results suggested that the speed of working memory updating not only influences the maintenance of sentence argument when the contents of working memory change but also influences the efficiency of integrating that argument with the verb at a late time point. When integrating the argument with the disambiguating verb, individuals with quick-updating ability can combine multiple sources of information (both noun animacy and word order), and conduct rapid and fine-grained two-stage processing; individuals with slow-updating ability, however, only rely on one dominant source of information types (word order), and conducted slow and course-grained processing.
    Cognitive Neurodynamics 12/2014; 8(6):447-464. DOI:10.1007/s11571-014-9292-2 · 1.77 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A carefully controlled study allowed us to compare the sensitivity of ASL (arterial spin labeling) and BOLD (blood oxygen level dependent) fMRI for detecting the effects of the adenosine A2a antagonist tozadenant in Parkinson disease. The study compared the effect of drug directly or the interaction of the drug with a cognitive task. Only ASL detected the direct effect of tozadenant. BOLD was more sensitive to the cognitive task, which (unlike most drugs) allows on-off comparisons over short periods of time. Neither ASL nor BOLD could detect a cognitive-pharmacological interaction. These results are consistent with the known relative advantages of each fMRI method, and suggest that for drug development, directly imaging pharmacodynamic effects with ASL may have advantages over cognitive-pharmacological interaction BOLD, which has hitherto been the more common approach to pharmacological fMRI.
  • Cognitive Computation 12/2014; 6(4):775-788. DOI:10.1007/s12559-014-9272-1 · 1.10 Impact Factor

Full-text (2 Sources)

Download
126 Downloads
Available from
May 23, 2014