title: Mona Lisa is always happy - and only sometimes sad.
abstract: The worldwide fascination of da Vinci's Mona Lisa has been dedicated to the emotional ambiguity of her face expression. In the present study we manipulated Mona Lisa's mouth curvature as one potential source of ambiguity and studied how a range of happier and sadder face variants influences perception. In two experimental conditions we presented different stimulus ranges with different step sizes between stimuli along the happy-sad axis of emotional face expressions. Stimuli were presented in random order and participants indicated the perceived emotional face expression (first task) and the confidence of their response (second task). The probability of responding 'happy' to the original Mona Lisa was close to 100%. Furthermore, in both conditions the perceived happiness of Mona Lisa variants described sigmoidal functions of the mouth curvature. Participants' confidence was weakest around the sigmoidal inflection points. Remarkably, the sigmoidal functions, as well as confidence values and reaction times, differed significantly between experimental conditions. Finally, participants responded generally faster to happy than to sad faces. Overall, the original Mona Lisa seems to be less ambiguous than expected. However, perception of and reaction to the emotional face content is relative and strongly depends on the used stimulus range.
authors.affiliation: Institute for Frontier Areas of Psychology and Mental Health, Freiburg, Germany.|Eye Center, Medical Center, University of Freiburg, Freiberg, Germany.|Center for Mental Disorders, Medical Center, University of Freiburg, Freiberg, Germany.|Faculty of Medicine, University of Freiburg, Germany.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Liaci
authors.affiliation: Institute for Frontier Areas of Psychology and Mental Health, Freiburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fischer
authors.affiliation: Laboratory for Biological and Personality Psychology, Department of Psychology, University of Freiburg, Freiberg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Heinrichs
authors.affiliation: Center for Mental Disorders, Medical Center, University of Freiburg, Freiberg, Germany.|Faculty of Medicine, University of Freiburg, Germany.
authors.forename: Ludger Tebartz
authors.initials: LT
authors.lastname: van Elst
authors.affiliation: Institute for Frontier Areas of Psychology and Mental Health, Freiburg, Germany.|Eye Center, Medical Center, University of Freiburg, Freiberg, Germany.|Center for Mental Disorders, Medical Center, University of Freiburg, Freiberg, Germany.|Faculty of Medicine, University of Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kornmeier
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004644:Emotions; D005149:Facial Expression; D005260:Female; D006240:Happiness; D006801:Humans; D008297:Male; D009144:Museums; D010151:Paintings; D010465:Perception; D011930:Reaction Time; D055815:Young Adult