Probing the causal involvement of dlPFC in directed forgetting using rTMS—A replication study

Verguts, T., Stauch, B. J., Braun, V. and Hanslmayr, S. (2020) Probing the causal involvement of dlPFC in directed forgetting using rTMS—A replication study. PLoS ONE, 15(8), e0236287. (doi: 10.1371/journal.pone.0236287) (PMID:32785218) (PMCID:PMC7423109)

Abstract

The forgetting of previously remembered information has, for a long time, been explained by purely passive processes. This viewpoint has been challenged by the finding that humans show worse memory for specific items that they have been instructed to forget. The dorsolateral prefrontal cortex has, through imaging, lesion and brain stimulation studies, been implied in controlling such active forgetting processes. In this study, we attempted to solidify evidence for such a causal role of the dlPFC in directed forgetting by replicating an existing rTMS study (Hanslmayr S, 2012) in a preregistered within-participant design. We stimulated participants at the dlPFC (BA9) or vertex using 45s of 1Hz rTMS after instructions to forget previously remembered words in a list-method directed forgetting paradigm and tested for effects on the amount of forgotten information. Contrary to the study we were attempting to replicate, no significant increase in forgetting under dlPFC stimulation was found in our participants. However, when combining our results with the study we were attempting to replicate, dlPFC stimulation led to significantly increased directed forgetting in both studies combined. We further explored if the rTMS parameters used here and in earlier work (Hanslmayr S, 2012) influenced inhibitory processing at their time of delivery or in a more persistent manner. Unaltered incongruency and negative priming effects in a Stroop task conducted directly after stimulation suggests that our rTMS stimulation did not continue to influence inhibitory processing after the time of stimulation. As the combined evidence for increased directed forgetting due to rTMS dlPFC stimulation is still quite weak, additional replications are necessary to show that directed forgetting is indeed causally driven by an active prefrontal process.

• Item Type: Articles
• Additional Information: SH was supported by the European Research Council (grant agreement No. 647954, https://erc.europa.eu), the Economic and Social Research Council (ESRC grant agreement No. ES/R010072/1, https://esrc.ukri.org), and Deutsche Forschungsgemeinschaft (HA 5622/1-1, https:// www.dfg.de/).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hanslmayr, Professor Simon

Creator Roles

Hanslmayr, S.: Conceptualization, Formal analysis, Funding acquisition, Methodology, Project administration, Resources, Supervision, Writing – review and editing

• Authors: Verguts, T., Stauch, B. J., Braun, V., and Hanslmayr, S.
• Subjects: B Philosophy. Psychology. Religion > BF Psychology; R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: PLoS ONE
• Publisher: Public Library of Science
• ISSN: 1932-6203
• ISSN (Online): 1932-6203
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in PLoS ONE 15(8):e0236287
• Publisher Policy: Reproduced under a Creative Commons License