The development of voluntary cardiovascular control

Several lines of evidence have suggested that the normally involuntary status of the autonomic nervous system is due to a lack of discriminable afferent information to the central nervous system. This proposition has been implicitly supported by many behavioral studies all of which provided extrinsic feedback of cardiovascular performance in an attempt to produce learned cardiovascular control. In order to explicitly determine whether discrimination of afferent information from the heart facilitates subsequent learned heart rate control, therefore, the first experiment of this dissertation was performed. During the first phase of this experiment, human subjects were trained to discriminate their pulses, and during the second phase; these same subjects were required to increase and decrease their heart rates under conditions of augmented sensory feedback of heart rate, and under conditions when no extrinsic feedback was provided. The results of this experiment demonstrated that a significant improvement in heart rate control during the second phase developed as a function of previous pulse discrimination training. In addition, pulse discrimination training facilitated the development of learned heart rate control under conditions of augmented sensory feedback. These findings were taken to support the original hypothesis that training designed to facilitate discrimination of the internal afferent information associated with a visceral response would also facilitate the development-learned control over that response. The results of this experiment together with other reports indicating that vo1untary visceral control is more effective under conditions of extrinsic response contingent feedback of visceral responding suggested the possibility that voluntary control might be developed over other aspects of cardiovascular functioning following the implementation of procedures which utilized augmented sensory feedback of the relevant response process. The second experiment in this dissertation investigated the possibility of producing voluntary control over changes in systolic blood pressure. During two training sessions, two groups of subjects were instructed to increase or decrease their systolic blood pressure while receiving virtually continuous extrinsic information of blood pressure changes. Heart rate was continuously monitored in all subjects to determine the relationship between changes in this cardiac response and systolic blood pressure. The results of this study demonstrated that following the implementation of a simple operant procedure, reliable increases and decreases in systolic blood pressure may be obtained, Moreover, such changes developed according to an instructional requirement and not as a function of habituation to the experimental environment, or as a result of unconditioned stimulus effects. Although these blood pressure changes were produced in the absence of any systematic changes in heart rate, it was found that increases and decreases in blood pressure ware associated with greater heart rate differences during certain periods in the development of learned blood pressure control than during other periods. The implications of these findings were discussed with respect to the use of visceral response discrimination and operant training procedures in the therapeutic control of emotional and psychosomatic behavior patterns.