Variation in normal mood state influences sensitivity to dynamic changes in emotional expression

Normal social functioning depends on the ability to efficiently and accurately detect when someone’s facial expression changes to convey positive or negative emotion. While observer mood state has been shown to influence emotion recognition, how variations in normal mood might influence sensitivity to the dynamic emergence of expressions has not yet been addressed. To investigate this, we modified an existing face morphing paradigm in which a central face gradually changes from neutral to expressive (angry, sad, happy, surprised). Our sample comprised healthy young adults and current mood state was measured using the PANAS-X. Participants pressed a key as soon as they (1) noticed a physical change in expression (‘perceptual sensitivity’ – novel task element), and (2) could clearly conceptualise which expression was emerging (‘conceptual sensitivity’). A final unspeeded response required participants to explicitly label the expression as a measure of recognition accuracy. We measured the percent morph (expression intensity) at which a perceptual and conceptual change was detected, where greater intensity equates to poorer sensitivity. Increased positive mood reduced perceptual and conceptual sensitivity to angry and sad expressions only (a mood incongruency effect). Of particular interest, increased negative mood decreased conceptual sensitivity for all expressions, but had limited impact on perceptual sensitivity. Thus, heightened negative mood is particularly detrimental for effectively decoding someone else’s mood change. This may reflect greater introspection and consumption of attentional resources directed towards the negative self, leaving fewer resources to process emotional signals conveyed by others. This could have important consequences for human social interaction.