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Pupil dilation reflects the authenticity of received nonverbal vocalizations

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Gonçalo Cosme, Pedro J. Rosa, César F. Lima, Vânia Tavares, Sophie Scott, Sinead Chen, Thomas D.W. Wilcockson, Trevor J. Crawford, Diana Prata

Original languageEnglish
Article number3733
JournalScientific Reports
Issue number1
PublishedDec 2021

Bibliographical note

Funding Information: DP was supported, during this work, by the European Commission Seventh Framework Programme Marie Curie Career Integration Grant FP7-PEOPLE-2013-CIG-631952, the 2016 Bial Foundation Psychophysiology Grant— Ref. 292/16, the Fundação para a Ciência e Tecnologia FCT IF/00787/2014, LISBOA-01-0145-FEDER-030907 and DSAIPA/DS/0065/2018 grants, and the iMM Lisboa Director’s Fund Breakthrough Idea Grant 2016; and is co-founder and shareholder of the neuroimaging research services company NeuroPsyAI, Ltd. VT was supported by an FCT PhD fellowship (PD/BD/114460/2016). GC was supported by an FCT PhD fellowship (SFRH/ BD/148088/2019). TJC and TW were support by the UK EPSRC grant EP/M006255/1. During the preparation of this manuscript, CL was supported by an FCT Investigator Grant (IF/00172/2015). The work was also supported by SynaNet Twinning Project which has received funding from the European Commission’s Horizon 2020 research and innovation programme under grant agreement No 692340. Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors


The ability to infer the authenticity of other’s emotional expressions is a social cognitive process taking place in all human interactions. Although the neurocognitive correlates of authenticity recognition have been probed, its potential recruitment of the peripheral autonomic nervous system is not known. In this work, we asked participants to rate the authenticity of authentic and acted laughs and cries, while simultaneously recording their pupil size, taken as proxy of cognitive effort and arousal. We report, for the first time, that acted laughs elicited higher pupil dilation than authentic ones and, reversely, authentic cries elicited higher pupil dilation than acted ones. We tentatively suggest the lack of authenticity in others’ laughs elicits increased pupil dilation through demanding higher cognitive effort; and that, reversely, authenticity in cries increases pupil dilation, through eliciting higher emotional arousal. We also show authentic vocalizations and laughs (i.e. main effects of authenticity and emotion) to be perceived as more authentic, arousing and contagious than acted vocalizations and cries, respectively. In conclusion, we show new evidence that the recognition of emotional authenticity can be manifested at the level of the autonomic nervous system in humans. Notwithstanding, given its novelty, further independent research is warranted to ascertain its psychological meaning.

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