Effects of instructions, biofeedback, and cognitive activities on heart rate control.

In a factorial experiment, 90 male and 90 female subjects were given (a) either instructions to increase heart rate (HR), decrease HR, or no instructions to change their HR; (b) either true biofeedback, false biofeedback, or no biofeedback; and (c) either instructions concerning cognitions to help them change HR or no instructions concerning cognitions. The results indicated that (a) for increasing HR, instructions to increase HR were as effective as the combination of instructions and true biofeedback; (b) for decreasing HR, neither instructions nor biofeedback nor the combination of instructions and biofeedback was more effective than simply sitting quietly; (c) although subjects instructed to increase HR showed higher HRs at the end of training than subjects instructed to decrease, the increase subjects showed a decline in HR from the initial period; (d) almost all subjects reported using cognitions to influence HR, and instructions concerning the use of cognitions did not facilitate changes in HR; and (e) women showed higher HRs, which declined more slowly than those of men, but sex did not interact with any treatment variable. It was concluded that increases (or retarded decreases) in HR were due to instructions, and decreases were due to simple adaptation, thus raising serious questions concerning the effectiveness of the biofeedback component of "biofeedback training" for altering HR.