Adaptive Control of Working Memory
Final Report Abstract
Human working memory (WM) is a highly flexible system optimized for guiding goal-directed (cognitive) actions. However, the flexibility of WM comes at the cost of a capacity limitation, requiring that the content of WM is continuously adapted to ongoing retrieval demands. The present project investigated how this is achieved by mechanisms of adaptive cognitive control. We focused on three well-known phenomena from the cognitive control literature: percentage congruency effects (PCE), congruency sequence effects (CSE), and post-error adjustments. While these three effects have previously been used to describe adaptive cognitive control in selective attention tasks, we here sought to establish equivalent effects in declarative WM to demonstrate how WM content is continuously adapted to expected and experienced retrieval conflicts. To this end, we used a modified Sternberg task (mixed-list paradigm) in which participants had to encode two lists of four numbers each, and later had to repeatedly retrieve numbers at specific position of one of the lists. While some positions contained the same numbers in both lists (congruent, low retrieval conflict), others contained different numbers in both lists (incongruent, high retrieval conflict). We showed that, during the retrieval phase, congruency effects (and thus interference in WM) varied as a function of the frequency of conflict trials (PCE) and of the conflict level of previous trials (CSE). Adaptive adjustments were obtained during retrieval but could not be demonstrated during encoding. Moreover, no post-error adjustments were observable. In EEG studies, we could demonstrate that retrieval conflict and its adjustment was reflected in an N450, suggesting a late, semantic level of interference. Conflict-based adjustments affected neural markers of WM load which offers the possibility that control processes optimize a trade-off between load and conflict. Taken together, we could show that adaptive control of WM follows similar principles as adaptive control of selective attention, which raises the possibility that control in both domains can be described by a unified theory.
Publications
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Adaptive control of working memory. In: A. C. Schütz, A. Schubö, D. Endres, & H. Lachnit (Eds.): Abstracts of the 60th Conference of Experimental Psychologists, Lengerich: Papst. (Talk)
Hartmann, E.-M.; Ochsenkühn, S.; Steinhauser, M. & Gade, M.
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Neuronal correlates of adaptive control in working memory. Psychophysiology, 56, 43-43. Poster presented at the 2018 Meeting of the Society for Psychophysiological Research, Washington D.C., USA.
Hartmann, E. M.; Gade, M. & Steinhauser, M.
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Behavioral and ERP measures of conflict adaptation in working memory. Poster presented at the 2020 virtual Meeting of the Cognitive Neuroscience Society.
Hartmann, E.-M.; Gade, M. & Steinhauser, M.
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EEG measures of conflict adaptation in working memory. Psychophysiology, 57, S37. Poster presented at the 2020 virtual Meeting of the Society for Psychophysiological Research.
Hartmann, E. M.; Gade, M. & Steinhauser, M.
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Adaptive control of working memory. Cognition, 224, 105053.
Hartmann, Eva-Maria; Gade, Miriam & Steinhauser, Marco
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Adaptive modulation of working memory load by redundancy. Poster presented at the 63rd Annual Meeting of the Society for Psychophysiological Research. New Orleans, USA.
Hartmann, E.-M. & Steinhauser, M.
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Neural correlates of adaptive cognitive control in working memory. Psychophysiology, 61(2).
Hartmann, Eva‐Maria; Gade, Miriam & Steinhauser, Marco
