1. How Sleep-Deprived People See and Evaluate Others’ Faces: An Experimental Study
- Author
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van Egmond LT, Meth EMS, Bukhari S, Engström J, Ilemosoglou M, Keller JA, Zhou S, Schiöth HB, and Benedict C
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sleep deprivation ,sleep ,eye-tracking ,gaze ,faces ,emotions ,Psychiatry ,RC435-571 ,Neurophysiology and neuropsychology ,QP351-495 - Abstract
Lieve T van Egmond,1,* Elisa MS Meth,1,* Shervin Bukhari,1 Joachim Engström,1 Maria Ilemosoglou,1 Jasmin Annica Keller,1 Shiyang Zhou,1 Helgi B Schiöth,2 Christian Benedict3 1Department of Surgical Sciences (Sleep Science Laboratory), Uppsala University, Uppsala, Sweden; 2Department of Surgical Sciences, Functional Pharmacology, Uppsala University, Uppsala, Sweden; 3Department of Pharmaceutical Biosciences, Molecular Neuropharmacology (Sleep Science Laboratory), Uppsala University, Uppsala, 751 24, Sweden*These authors contributed equally to this workCorrespondence: Lieve T van Egmond, Department of Surgical Sciences (Sleep Science Laboratory), Uppsala University, Husargatan 3, Box 593, Uppsala, 751 24, Sweden, Tel +46 18-4714123, Email lieve.van.egmond@neuro.uu.seBackground: Acute sleep loss increases the brain’s reactivity toward positive and negative affective stimuli. Thus, despite well-known reduced attention due to acute sleep loss, we hypothesized that humans would gaze longer on happy, angry, and fearful faces than neutral faces when sleep-deprived. We also examined if facial expressions are differently perceived after acute sleep loss.Methods: In the present, within-subjects study, 45 young adults participated in one night of total sleep deprivation and one night with an 8-hour sleep opportunity. On the morning after each night, an eye tracker was used to measure participants’ time spent fixating images of happy, angry, fearful, and neutral faces. Participants also evaluated faces’ attractiveness, trustworthiness, and healthiness on a 100-mm visual analog scale.Results: Following sleep loss, participants struggled more fixating the faces than after sleep. The decrease in total fixation duration ranged from 6.3% to 10.6% after sleep loss (P< 0.001). Contrary to our hypothesis, the reduction in total fixation duration occurred irrespective of the displayed emotion (P=0.235 for sleep*emotion interaction) and was also present for the upper (P< 0.001) but not the lower part of the faces (except for the lower part of angry faces). Overall, faces were evaluated as less trustworthy (− 2.6 mm) and attractive (− 3.6 mm) after sleep loss (p< 0.05).Discussion: Facial expressions are crucial for social interactions. Thus, spending less time fixating on faces after acute sleep loss may come along with several problems for social interactions, eg, inaccurate and delayed judgment of the emotional state of others. In addition, more negative social impressions of others may lead to social withdrawal in sleep-deprived humans.Keywords: sleep deprivation, sleep, eye-tracking, gaze, faces, emotions
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- 2022