Exploring the left eye bias for faces
33.53, Sunday, May 12, 8:30 am - 12:30 pm, Vista Ballroom
Elina Birmingham1, Dawn Chan1, Victoria Kling1, Dominic Trevisan1; 1Faculty of Education, Simon Fraser University
Observers show an attentional bias for the left visual field (LVF) relative to the right visual field (RVF) of face stimuli (e.g., Butler et al., 2005 Neuropsychologia). Recent work using the Moving Window Technique (MWT) revealed that a specific bias to explore the eye region within the LVF (LVF-eye) emerges at 11-12 years of age and reaches significance in adulthood (Birmingham, Meixner, Iarocci, Kanan, Smilek, & Tanaka, in press at Child Development). The present study examined whether the LVF-eye bias is modulated by the type of expression (basic vs. complex expressions). In the MWT, the observer explores a blurry face with a mouse-controlled window of high-resolution information. Experiment 1: 64 images consisting of four basic expressions (happy, angry, fearful, disgusted) were presented (n=17). Experiment 2: 20 images of basic (e.g., sad, afraid, angry) and complex (e.g., admiring, guilty, flirting) expressions were presented (n=9; preliminary data). In both experiments, the starting position of the exploration window was counterbalanced, occurring to the left or the right of the face on alternating trials. Experiment 1: the LVF-eye was explored more than the RVF-eye (LVF-eye M=0.24 vs. RVF-eye M=0.16), p<0.05. The bias to explore the LVF-eye did not vary as a function of emotion (happy, angry, fearful, disgusted). In Experiment 2, the LVF-eye bias was stronger for complex expressions (LVF-eye M=0.25 vs. RVF-eye M=0.19) than for basic expressions (LVF-eye M=0.22 vs. RVF-eye M=0.20), p<0.05. Exploration of the mouth was reduced for complex expressions relative to basic expressions. The LVF-eye bias is enhanced for complex expressions, suggesting a functional role in expression recognition.