Hemispheric asymmetries in attentional control: implications for hand preference in sensorimotor tasks.

Liepmann (1908) proposed that handedness reflects the greater capacity of one hemisphere to learn the execution of skilled movements. Although asymmetries in motor control are an important basis for hand asymmetries, recent studies have suggested that handedness may be determined by multiple factors. In the present study, we examine how attentional asymmetries may contribute to hand preferences. Right-handed subjects participated in a reaction time task in which they were given preliminary information about where a target stimulus would occur (selective attention) or which hand to use for responding (selective intention). Our findings indicate that these processes influence each other reciprocally and favor a state of optimal attentional and intentional preparation of the right hand. We suggest that these hemispheric asymmetries in attentional control contribute to hand preferences in certain sensorimotor tasks.