Tactile recognition of laterally inverted mirror images by children: intermanual transfer and rotation of the palm.

Intermanual tactile recognition of laterally inverted mirror shapes was studied, with special reference to the role of the thumb. Children were allowed to feel the shapes either with the whole hand, with only four fingers (excluding the thumb), or with only the index finger. Intramanual recognition was also studied after rotation of the hand from the palm down/up to the palm up/down orientation. The thumb was found not to be important for intermanual mirror reversals, and only of limited importance for intramanual reversals. There was no evidence that coding with reference to the hand is of importance for either inter or intramamual reversals. The explanations for the two kinds of reversals are quite different.