Manual performance on the GATB as a screening measure for neurological impairment

This study study investigates the effect of practice order and initial hand performance on laterality. Thirty-two right handed subjects, ages 19-42, performed 3 trials on a manual dexterity task (General Aptitude Test Battery- Turn) with each hand. Half of the subjects performed with their preferred hand first, using the nonpreferred hand on the subsequent 3 trials. The order of administration was reversed for the other subjects. Each subject also completed the Quick Neurological Screening Test. The degree of manual specialization (functional asymmetry between the hands) on the pegboard task was not correlated with performance on the Quick Neurological Screening Test (QNST). Level of manual dexterity (total number of pegs turned) was correlated with the QNST. Both hands showed improvement over practice, but the preferred hand superiority existed. Order of administration influenced laterality, with the left/right order of administration showing more manual specialization than the reversed order of administration. The results provide support for left hemisphere control of movement sequencing. The effect of practice order and hand performance on laterality is discussed.