Development of proprioceptive sensitivity.

The development of proprioceptive sensitivity was studied in 140 children between the ages of 5.8 and 11.8 years using a so-called foot-hand task. Ten boys and ten girls were included in each age group. The task required the children to locate a target pin with the "big toe" (felt target) and match the located target position with the hand, without vision. There were four conditions: location of targets by the right big toe: matching located target position with the right hand (RfRh) and left hand (RfLh); and location of targets by the left big toe: matching located target position with the left hand (LfLh) and right hand (LfRh). The results showed a significant developmental trend in proprioceptive sensitivity, when the absolute error scores for boys and girls were combined, with most of the improvement occurring between the ages of 5.8 and 7.8 years. The most interesting and novel finding seems to be the significant two-way interaction between age and sex--the clearest differences manifesting themselves in the age group 9.9 years. Separate within-sex group analyses showed the trend to be determined by the results for the girls, the trend being absent in the results for the boys. Furthermore only the boys showed a significant difference between the intra- and inter-hemispheric conditions. We propose that these differences may only manifest themselves in particular tasks, i.e. there may be a sex-task interaction. The implications of this proposal for theoretical interpretations of the phenomenon of inter-hemispheric processing as well as possible sources of the task differences are briefly discussed.