The Presentation Location of the Reference Stimuli Affects the Left-Side Bias in the Processing of Faces and Chinese Characters.

Chenglin Li,Xiaohua Cao

doi:10.3389/fpsyg.2017.01673

Abstract

For faces and Chinese characters, a left-side processing bias, in which observers rely more heavily on information conveyed by the left side of stimuli than the right side of stimuli, has been frequently reported in previous studies. However, it remains unclear whether this left-side bias effect is modulated by the reference stimuli's location. The present study adopted the chimeric stimuli task to investigate the influence of the presentation location of the reference stimuli on the left-side bias in face and Chinese character processing. The results demonstrated that when a reference face was presented in the left visual field of its chimeric images, which are centrally presented, the participants showed a preference higher than the no-bias threshold for the left chimeric face; this effect, however, was not observed in the right visual field. This finding indicates that the left-side bias effect in face processing is stronger when the reference face is in the left visual field. In contrast, the left-side bias was observed in Chinese character processing when the reference Chinese character was presented in either the left or right visual field. Together, these findings suggest that although faces and Chinese characters both have a left-side processing bias, the underlying neural mechanisms of this left-side bias might be different.

Highlights

Adults are experts at recognizing human faces and words
The primary purpose of the present study was to examine how the visual field, where the original stimulus is presented in the chimeric paradigm, modulates the left-side bias in both face and Chinese character processing
In Experiments 1 and 2, the results showed that, for the first time, when an original face was presented in the left visual field, the preference for the left chimeric face was higher than no-bias threshold, but this effect was not observed in the right visual field

Summary

Introduction

Adults are experts at recognizing human faces and words. Many behavioral effects have been used to investigate the mechanism of the perceptual expertise, for instance, the inversion effect (e.g., Yin, 1969; Haxby et al, 1999), the composite effect (for a review, see Richler and Gauthier, 2014), and the left-side bias (e.g., Gilbert and Bakan, 1973; Hsiao and Cottrell, 2009; Proietti et al, 2015). In a facial expression judgment task, Wolff (1933) first observed the left-side bias effect This effect was later replicated by Gilbert and Bakan (1973) in a face perception judgment task, and it has been found in tasks involving the processing of other aspects of faces, such as facial identity (e.g., Coolican, et al, 2008; Proietti et al, 2015), emotion (e.g., David, 1993; Ferber and Murray, 2005; Bourne, 2008, 2011; Coolican, et al, 2008), gender (e.g., Luh et al, 1991; Butler and Harvey, 2005, 2008), age and attractiveness (e.g., Burt and Perrett, 1997), and aesthetic preferences (e.g., Heath et al, 2005).

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