FIG. 5.

Representative raw record showing GG single motor-unit activities during unimpeded and impeded protrusion trials (see text for details). Top: force trace (as depicted in Fig. 1A); force was not measured in unimpeded protrusion trials and thus is set to zero. Middle: position of tongue relative to the neutral or rest position (mm). Lower: instantaneous firing rate (dots). Bottom: Discriminated GG motor-unit potentials; inset shows overlay of 35 consecutive potentials of the identified unit from each trial.