Physiology of animal behavior: dynamics of chimpanzee heart rhythm during perception of an emotionally charged human voice.

Abstract

1. Negative voice and rejected direct stimuli were identical in effective physiological force for young chimpanzees age 6–7 years. 2. Negatively charged voice stimulus as well as the negative direct stimulus evoked a reliable slowing of the heart rhythm relative to both the initial state and to the effect of the positive signal. 3. Negative voice and direct stimuli had a longer lasting effect on the cardiovascular system than positive stimuli. 4. We found a stable individual specificity of changes in heart contraction frequency in response to negative voice and direct stimuli in the young chimpanzees studied.