Fig. 6
From: Mothers’ pupillary responses to infant facial expressions
Pupil diameter during constriction (lower half) and dilation phase (upper half) in response to negative and positive facial expression of emotion and to luminance-matched non-face stimuli (scrambled pixels). Greater pupil dilation was elicited by negatively-valenced than by positively-valenced faces. No such difference in dilation was found across non-face stimuli. While the effect of valence on pupil size was found also during the constriction phase, this effect was not unique to face stimuli. Data from the control experiment (Experiment 2, N = 15). Error bars indicate standard errors of the mean. ***p < .001, n.s. not significant