Surface electromyography (EMG) has been a powerful technique for studying r
eflex and other stimulus-evoked responses in the human nervous system. Howe
ver, important additional insights can be gained into the operation of neur
al circuits by studying the responses of single motor units to various stim
uli. In this paper, some of the advantages of single motor unit recording w
ill be canvassed, and some examples of the application to this method to th
e study of reflex responses to sensory stimuli and brain stimulation will b
e presented. (C) Elsevier, Paris.