EMG biofeedback: The effects of CRF, FR, VR, FI, and VI schedules of reinforcement on the acquisition and extinction of increases in forearm muscle tension

Biofeedback was used to increase forearm-muscle tension. Feedback was deliv ered under continuous reinforcement (CRF), variable interval (VI), fixed in terval (FI), variable ratio (VR), and fixed ratio (FR) schedules of reinfor cement when college students increased their muscle tension (electromyograp h, EMG) above a high threshold. There were three daily sessions of feedback , and Session 3 was immediately followed by a session without feedback (ext inction). The CRF schedule resulted in the highest EMG, closely followed by the FR and VR schedules, and the lowest EMG scores were produced by the FI and VI schedules. Similarly, the CRF schedule resulted in the greatest amo unt of time-above-threshold and the VI and FI schedules produced the lowest time-above-threshold. The highest response rates were generated by the FR schedule, followed ky the VR schedule. The CRF schedule produced relatively low response rates, comparable to the rates tinder the VI and Fl schedules . Some of the data are consistent with the partial-reinforcement-extinction effect. The present data suggest that different schedules of feedback shou ld be considered in muscle-strengthening contexts such as during the rehabi litation of muscles following brain damage or peripheral nervous-system inj ury.