| Sumario: | A study reviewed the neurophysiological and behavioral evidence that manual gestures and vocal language share the same control systems. The research on human and primate premotor cortex and, specifically, on the so-called “mirror systems” pointed to the existence of a dual hand/mouth motor command system involved in ingestion activities. This command system could be the foundation for the creation of a combined manual and vocal communication system. In humans, manual gestures typically accompany speech, influence speech production itself, and play a vital role in the development of speech from the babbling stage onward. Behavioral data indicated a reciprocal effect between word and symbolic gestures, and neuroimaging and repetitive transcranial magnetic stimulation data yielded evidence that the system governing both speech and gesture is situated in Broca's area. The findings suggest that the hand motor-control system is involved in higher order cognition.
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