Assimetrias laterais em acoes motoras: preferencia versus desempenho

Abstract

Lateral Asymmetries In Motor Actions: Preference Versus Performance. Asymmetries in lateral preference are frequently treated as a synonym for lateral dominance, a concept that expresses the supremacy of performance with a limb over the contralateral homologous limb. This concept usually also implies that lateral asymmetries are rarely affected by environmental factors. In this investigation the index of manual preference was compared and correlated to the index of performance asymmetry on three motor tasks: (a) repeated tapping, (b) manual force control, and (c) linear arm positioning. The results showed that lateral preference asymmetries were considerably higher than performance asymmetries. Between-hand comparison for each task did not indicate significant differences for force control and arm positioning, but consistent superiority of performance with the preferred hand for repeated tapping. Furthermore, no significant correlations were found either between preference and performance asymmetries or between indexes of performance asymmetry. This indicates that the observed asymmetry of performance is task-specific and cannot be predicted from a general quotient of lateral preference. Such results suggest the participation of environmental factors in the determination of lateral dominance.