Performance of the manual and oral-motor systems using the dual-task paradigms

A single experiment was conducted to examine interference in the oral-motor and manual output systems when using the dual-task paradigm. The manual ta sk involved a repetitive and sequential finger tapping condition, right and left hand. A concurrent verbal task involving a series of bilabial syllabl es enabled the experimenters to quantify the patterns of oral-motor output during different finger tapping conditions. The results indicated a unidire ctional pattern of asymmetry, involving only the oral-motor system when the manual task was performed sequentially or with the right hand. These data provide support for a lateralized "praxis'' system in the left hemisphere. (C) 1999 Academic Press.