Sex Differences in Processing Movement vs Objects Figure 2. Data shown in the upper panel are the mean (±SEM) for target accuracy measured under egocentric and allocentric perspectives for 18 males and 17 females tested in Experiment 1. Data are expressed as millimeters of deviation from zero. *p,0.05, **p,0.01 from males in same condition/speed. Mean reaction times (6SEM) for the targeting response are shown the lower panel. doi:10.1371/journal.pone.0032238.g002 participants in the dual attention condition were not tested for targeting and color alone. When participants were tested for targeting and color recognition alone in Experiment 4 before being tested in the dual attention condition, the sex difference was present in the targeting alone condition, but males performed significantly worse in the dual attention condition for both targeting and color shade recognition, whereas females showed no significant change. While these results are consistent with a male bias toward movement that was compromised by requiring them to prepare for both movement and object recognition under dual attention conditions, the color recognition results suggest that the dual attention condition causes attentional interference in males that is not observed in females. When we tested color shade recognition alone in Experiments 2 and 4, we observed no sex difference in recognition accuracy. However, in the dual attention condition in Experiments 3 and 4, male accuracy was significantly poorer than female accuracy at the slow ball speeds (4–5 cm/sec) but not the fast speed (8 cm/sec). Thus, the dual attention condition induced poorer performance for both targeting and color recognition in males, but not females. This pattern of attentional interference in males could arise from a male preference for using a bottom-up processing strategy for the targeting task, in contrast with the top- down processing required for object recognition. This would PLoS ONE | www.plosone.org 5 March 2012 | Volume 7 | Issue 3 | e32238