Distractor-resistant short-term memory is supported by transient changes in neural stimulus representations

Derrfuss, Jan and Ekman, Matthias and Hanke, Michael and Tittgemeyer, Marc and Fiebach, Christian J. (2017) Distractor-resistant short-term memory is supported by transient changes in neural stimulus representations. Journal of Cognitive Neuroscience, 29 (9). pp. 1547-1565. ISSN 1530-8898

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Abstract

Goal-directed behavior in a complex world requires the maintenance of goal-relevant information despite multiple sources of distraction. However, the brain mechanisms underlying distractor-resistant working or short-term memory (STM) are not fully understood. While early single-unit recordings in monkeys and fMRI studies in humans pointed to an involvement of lateral prefrontal cortices, more recent studies highlighted the importance of posterior cortices for the active maintenance of visual information also in the presence of distraction. Here, we used a delayed match-to-sample task and multivariate searchlight analyses of fMRI data to investigate STM maintenance across three extended delay phases. Participants maintained two samples (either faces or houses) across an unfilled pre-distractor delay, a distractor-filled delay, and an unfilled post-distractor delay. STM contents (faces vs. houses) could be decoded above-chance in all three delay phases from occipital, temporal, and posterior parietal areas. Classifiers trained to distinguish face vs. house maintenance successfully generalized from preto post-distraction delays and vice versa, but not to the distractor delay period. Furthermore, classifier performance in all delay phases was correlated with behavioral performance in house, but not face trials. Our results demonstrate the involvement of distributed posterior, but not lateral prefrontal, cortices in active maintenance during and after distraction. They also show that the neural code underlying STM maintenance is transiently changed in the presence of distractors, and re instated after distraction. The correlation with behavior suggests that active STM maintenance is particularly relevant in house trials, whereas face trials might rely more strongly on contributions from long-term memory.

Item Type: Article
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Psychology
Identification Number: 10.1162/jocn_a_01141
Related URLs:
Depositing User: Eprints, Support
Date Deposited: 10 Apr 2017 10:47
Last Modified: 04 Nov 2017 10:56
URI: http://eprints.nottingham.ac.uk/id/eprint/41857

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