A smile biases the recognition of eye expressions: Configural projection from a salient mouth

Abstract

A smile is visually highly salient and grabs attention automatically. We investigated how extrafoveally seen smiles influence the viewers' perception of non-happy eyes in a face. A smiling mouth appeared in composite faces with incongruent non-happy (fearful, neutral, etc.) eyes, thus producing blended expressions, or it appeared in intact faces with genuine expressions. Attention to the eye region was spatially cued while foveal vision of the mouth was blocked by gaze-contingent masking. Participants judged whether the eyes were happy or not. Results indicated that the smile biased the evaluation of the eye expression: The same non-happy eyes were more likely to be judged as happy and categorized more slowly as not happy in a face with a smiling mouth than in a face with a non-smiling mouth or with no mouth. This bias occurred when the mouth and the eyes appeared simultaneously and aligned, but also to some extent when they were misaligned and when the mouth appeared after the eyes. We conclude that the highly salient smile projects to other facial regions, thus influencing the perception of the eye expression. Projection serves spatial and temporal integration of face parts and changes.

Keywords:

• Facial expression
• Smile
• Saliency
• Projection
• Configural
• Recognition

Acknowledgments

This research was supported by Grant PSI2009-07245 from the Spanish Ministerio de Ciencia e Innovación, and the Agencia Canaria de Investigación, Innovación, y Sociedad de la Información (Neurocog Project), and the European Regional Development Fund, to MGC and AFM, and by the Academy of Finland Grant #217995, and the AivoAalto grant from Aalto University, to LN.

Notes

¹ An alternative way of investigating the smile projection effect would involve facial inversion. Hills, Sullivan, and Pake (2012) found that more fixations of a shorter duration were made to inverted faces than to upright faces. This is consistent with Rossion's (2009) work suggesting that inversion restricts the perceptual field: Whereas an upright face can be holistically sampled from a central fixation, in an inverted face each feature has to be sampled independently. This implies that the radius of extrafoveal projection of non-fixated facial features could be reduced by inversion, thus limiting the influence of the (non-fixated) smiling mouth.