Individual data of "Shirai et al. (submitted). Differences in the magnitude of representational momentum between school-aged children and adults as a function of experimental task"

Representational momentum (RM) is the phenomenon that occurs when an object moves and then disappears, and the recalled final position of the object shifts in the direction of its motion. Findings on the magnitude of RM exhibited during childhood are not completely consistent. Some findings indicate that the magnitude of RM in early childhood is comparable to that in adulthood, while others suggest that the magnitude of RM is significantly greater in childhood than in adulthood. We examined whether the inconsistencies between the previous studies could be explained by the difference in the experimental tasks used in these studies. In one study, a same–different judgment between the position at which a moving stimulus disappeared and that at which a comparison stimulus reappeared, called a judging task, was used. In another study, the participants pointed to the position at which the moving stimulus disappeared using a computer mouse cursor. This was called a pointing task. We examined RM in both the judging and pointing tasks and found that, for the judgment task, there was no significant difference in the magnitude of RM among all age groups tested: younger children, mean age = 7.4 years; older children, mean age = 10.7 years; adults, mean age = 22.1. However, in the pointing task, the younger children exhibited a significantly greater RM magnitude than did adults. We discuss possible reasons for the inconsistent developmental trends shown by the two different tasks, namely lower visual motion sensitivity in childhood.