Number magnitude determines gaze direction: Spatial-numerical association in a free-choice task

Since Dehaene et al. (1993) reported the SNARC (Spatial-Numerical Association of Response Codes) effect, researchers have repeatedly documented an influence of number magnitude on reaction time in various motor tasks. In addition, thinking about numbers induces shifts of visuo-spatial attention (Fischer et al., 2003). The present study examined whether number magnitude affects a person's eye movement in a free-choice task. After the presentation of a number in the middle of the screen, two pictures of human faces were simultaneously presented on either side of the screen. Participants were asked to explore the screen after the presentation of a number. Analyses performed on first eye fixations confirmed that number magnitude affects gaze direction in this free-choice task. The present study shows that the influence of number magnitude on visuo-spatial attention affects the choice of where to look first.