Hemispheric asymmetry and dual-task performance in children: a finger-tapping study.

The aim of the present experiment was to investigate effects of concurrent verbal and nonverbal cognitive tasks on right- and left-hand finger-tapping in right-, and left-handed boys and girls, within a dual-task paradigm. There were three interference tasks used: one motor verbal (reading aloud), and two sensory-memory tasks (cards with nonsense syllables and random shapes). Interference has been observed in adults in previous studies, and the first question was whether interference would be observed in the same manner in children. Furthermore, when comparing right- and left-handed boys and girls within the same study, possible effects of sex and hand preference could be evaluated. The final question addressed was whether there would be differences between the verbal and nonverbal tasks. The results revealed decreased tapping frequency bilaterally for all groups during execution of the motor verbal task. Furthermore, significant differences were found between boys and girls when tapping to the two sensory tasks, and particularly when tapping with the right hand. In left-handers, interference was most pronounced for the left-handed girls. As a conclusion, dual-task interference seems to be more pronounced in children as compared to adults. This might be due to interference caused by increased requests for general process capacity.