Fine-grained sensitivity to vertical differences in triadic gaze is slow to develop

Adults use the direction of gaze toward objects in the environment (triadic gaze) to make judgments about the focus of a person’s visual attention. Adults are able to detect horizontal and vertical differences of ~1° in the target of triadic gaze (Bock et al., 2008; Symons et al., 2004). Children’s sensitivity to horizontal differences becomes adult-like around age 10, with a 50% increase in sensitivity after age 6 (Vida & Maurer, 2012). In Experiment 1, we used a child-friendly method to compare sensitivity to vertical differences between 6-, 8-, 10-, 14-year-olds and adults (n=18/age group). Participants viewed photographs of faces fixating a vertical series of points (separated by 1.6°) that were physically marked on a board between the observer and the monitor. Participants pressed a key to indicate whether a face appeared to be looking above or below a designated target position, which was positioned at the eye height of the model and observer or 6.4° above or below it. At age 6, thresholds were small (M=1.53°), but were larger than those of adults (M=.88°), p<.005. Thresholds did not decrease to adult levels until around age 14. All age groups displayed lower sensitivity for the upper target (M=1.37°) than the target at eye height (M=1.14°), p<.01, and an upward bias of ~1° for the upper and eye height targets, ps<.01. Experiment 2 indicated that at least some of the developmental change arises from children’s lower sensitivity to vertical differences in eye position. Specifically, 8- (M=.73) and 10-year-olds (M=.76) were less accurate than adults (M=.83) at detecting vertical mismatches in the direction of gaze between simultaneously presented faces, ps<.002 (n=18/age group). These results indicate that until after age 10, children’s judgments about the focus of others’ attention are limited by insensitivity to vertical gaze cues. Meeting abstract presented at VSS 2012