Operant conditioning of a small-scale muscle response.

Six naive male subjects were reinforced for responses in the 20-30 microvolt range, and two each for those in 10-20 and 30-40 microvolt ranges. Records were taken of 15 min of "settling down," 15 min of initial operant level responding, 30 min of conditioning, and 45 min of extinction, 30 min with light present and 15 min without. The results were: (1) small-scale muscle potentials from the thenar eminence, in the 10-20, 20-30, and 30-40 microvolt ranges, were conditioned, using pointer movement as the reinforcement; (2) the response rate in adjacent ranges of greater and lesser amplitude also increased during such conditioning and decreased during the subsequent extinction; (3) during conditioning the frequency of response distribution shifted toward the reinforced range; (4) subjects were unaware of the reinforced response; (5) observing a noncontingent moving pointer increased the response rate in the 20-30 microvolt range, but did not lead to conditioning.