Abstract
Adults are able to determine which object in the environment someone is looking at with high precision (triadic gaze). By age 6, children can detect large (10°) differences in triadic gaze (Doherty et al., 2009). Here, we developed a child-friendly procedure to compare sensitivity to small horizontal differences in triadic gaze between 8-year-olds and adults (n = 18/group). Participants sat in front of a computer monitor on which they saw faces fixating a series of points (separated by 1.6°) that were physically marked on a board halfway between them and the monitor. The task was to indicate whether each face appeared to be looking to the left or right of one of three target points (center, 6.4° left or 6.4° right). All participants were at least 75% correct on a practice block completed before each experimental block. Adults were highly sensitive to deviations from the central target, with a mean error of 0.83° (calculated from the .25 and .75 points on the fitted psychometric curves). 8-year-olds were not as sensitive (M error = 2.05°, p <.0001). When the targets were peripheral, participants overestimated the degree to which the face was looking toward the periphery (e.g., judging the face to be looking to the left of the left target), with a larger error in children (M = 2.26°) than in adults (M = 0.91°, p <.05). Relative to 8-year-olds, 10-year-olds (n = 10 tested to date) appear to show a more adult-like pattern characterized by a steeper slope and a more adult-like asymptote. These results indicate for the first time that by age 8, children can detect small differences in triadic gaze, but that sensitivity is not yet as refined as it will become in adulthood.
Canadian Natural Sciences and Engineering Research Council (NSERC).