The effect of lithium treatment in humans of psychophysiological increases and decreases in heart rate

Abstract

Two psychophysiological heart rate response phenomena have been noted and investigated in the literature: heart rate acceleration and heart rate deceleration. These two responses of the cardiovascular system have been associated with cognitive functioning and orienting response situations, respectively. In the 1950’s, it was believed that increased sympathetic activity had an excitory and facilitating effect, serving to provoke or maintain cortical activation. Lacey (1) observed that this did not hold for increases in heart rate and blood pressure. He claimed that heart rate increase would most likely be coupled with a reduced sensitivity to stimulation. Lacey proposed that heart rate increase should be associated with lowered sensitivity to the environment and should occur in situations of painful or unpleasant stimulation, or in situations where external distractions would interfere with internal prob lern-solving. Conversely, Lacey postulated that heart rate decrease should be associated with heightened sensitivity to stimulation and should occur in a situation requiring “attention”. These proposals were confirmed by Obrist (2). Cardiac changes were also seen by Sokolov (3) to be under the control of environmental inputs. He considered these changes to be a component of the orienting response, defined as a functional system which enhances sensitivity to external stimuli. Sokolov did not discuss the significance of the direction of cardiac change. However, on the basis of Lacey’s work, deceleration would be expected.