title: Neural correlates of verbal joint action: ERPs reveal common perception and action systems in a shared-Stroop task.
abstract: Recent social-cognitive research suggests that the anticipation of co-actors' actions influences people's mental representations. However, the precise nature of such representations is still unclear. In this study we investigated verbal joint representations in a delayed Stroop paradigm, where each participant responded to one color after a short delay. Participants either performed the task as a single actor (single-action, Experiment 1), or they performed it together (joint-action, Experiment 2). We investigated effects of co-actors' actions on the ERP components associated with perceptual conflict (Go N2) and response selection (P3b). Compared to single-action, joint-action reduced the N2 amplitude congruency effect when participants had to respond (Go trials), indicating that representing a co-actor's utterance helped to dissociate action codes and attenuated perceptual conflict for the responding participant. Yet, on NoGo trials the centro-parietal P3 (P3b) component amplitude increased for joint-action, suggesting that participants mapped the stimuli onto the co-actor's upcoming response as if it were their own response. We conclude that people represent others' utterances similarly to the way they represent their own utterances, and that shared perception-action codes for self and others can sometimes reduce, rather than enhance, perceptual conflict.
authors.affiliation: Laboratory of Neuroimaging, NIAAA, National Institutes of Health, 10 Center Drive, Bldg. 10, B2L124, Bethesda, MD 20892, USA; Department of Psychology, The University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK. Electronic address: sukru.demiral@nih.gov.
authors.forename: Şükrü Barış
authors.initials: ŞB
authors.lastname: Demiral
authors.affiliation: Department of Psychology, The University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK.
authors.forename: Chiara
authors.initials: C
authors.lastname: Gambi
authors.affiliation: Department of Psychology, The University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK.
authors.forename: Mante S
authors.initials: MS
authors.lastname: Nieuwland
authors.affiliation: Department of Psychology, The University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Pickering
keywords: ERP; Joint action; Language; Shared representations; Stroop