Maturation and the spiral aftereffect.

"The spiral aftereffect technique was administered to 81 children ranging in age from 48 to 71 months. No children below 55 months reported the aftereffect, while all of those above 69 months were able to report the phenomenon. Mental age was found to bear a more direct relationship to perception of the aftereffect than chronological age. The results of this study lend support to the hypothesis that children below a certain age level, presumably because of insufficient neural maturation, exhibit some behaviors similar to those of brain injured adults." (PsycINFO Database Record (c) 2010 APA, all rights reserved)