Published online by Cambridge University Press: 01 August 1998
The evolutionary continuity between the prespeech functions of premotor cortex and its new linguistic functions, the main thesis of MacNeilage's target article, is confirmed by the recent discovery of “mirror” neurons in monkeys and a corresponding action-observation/action-execution matching system in humans. Physiological data (and other considerations) appear to indicate, however, that brachiomanual gestures played a greater role in language evolution than MacNeilage would like to admit.