Right-left orientation and significance of systematic reversal in children

Shortly before the acquisition of right and left, which generally occurs ar ound age 6-7 years, a very simple right/left discrimination task makes it p ossible to distinguish groups of children with strikingly different cogniti ve abilities. Preschool children aged from 5 to 6.4 years were asked to sho w their left hand, right eye, left ear and right hand. On a variety of simp le cognitive tasks exploring verbal fluency, syntactic comprehension, worki ng memory, visuo-spatial ability and number processing, children who made f rom 1 to 3 errors (14% of the sample) performed significantly worse than th ose who showed systematic reversal (30%) and those who made no error. Diffe rential use of logical thinking can partially explain these differences. Ne uropsychological implications of these developmental findings are discussed .