The integration of sensory information in the development of precise manual pointing.

The development of manual pointing was studied in 270 children from 4 yr of age to 12 yr of age. Fifteen boys and 15 girls were included in each age group. The task was to place pins underneath a table-top at positions seen or felt on the table-top. Each child was tested in four different conditions: both visual and proprioceptive information about the position of the dot to be pointed at could be provided, just one of these two sources of information could be provided, or none of them. Errors were analysed in terms of systematic and random error. The results show that in all age groups, performance was superior when visual information about the position of the dot was provided. The ability to utilize visual information was found to be rather good already at the youngest ages. In the visual conditions the random error decreased with age in a gradual and linear fashion but the systematic error did not, it decreased and increased and decreased again. Errors were substantially smaller at 7 and 11 yr of age. The ability to use information from the proprioceptors improved remarkably during the youngest ages. All the improvement of the random error between 4 and 5 yr of age could be attributed to this factor. The systematic error in all conditions was found to be displaced towards the contralateral side of the body, but this effect was strongest in the proprioceptive condition. A strong interaction between sex and hand used in pointing was found in the systematic errors but none in the random errors. The interaction could be described as a nondominant hand disadvantage of the girls.

RCT Entities:   Population Interventions Outcomes