Intrahemispheric interaction between speaking and sequential manual activity

Abstract

Previous studies have suggested an interaction between speaking and manual activity. This interaction was examined using concurrent speaking and an equivalent non-speech vocalization condition with four motor tasks performed by left and right hands separately. In a dowel balancing task, intereference was present only during non-speech vocalization over all subjects. In right-handers interference occured only during speaking for single finger tapping and two sequential tasks. In single finger tapping this interference was present on both left and right hands; in the two sequential tasks speaking interfered selectively with right hand performance. The results are taken to suggest an overlap in cerebral representation of speaking and certain manual activities; some possible mechanisms underlying this are further discussed.