Heart Activity and Behavior I: Developmental Factors, Motor and Mental Activities, Perception, Attention, and Orienting Responses
Why should the heart be of interest in psychophysiological research? After all, it is merely a muscular pump that pushes out blood to the rest of the body. This is true, but as we noted in chapter 1, there are written records to show that very early scientists observed that changes in cardiac activity were related to psychological phenomena and emotions such as "love sickness." In fact, it is more than likely that changes in heart activity that occurred in amorous or fear-producing situations were noticed by cavepeople thousands of years ago. The association of the heart with love, cupid's bow, and Valentine's day also reflects individual perceptions of heartbeat changes that occur with emotional reactions. Contemporary cardiovascular psychophysiologists (and cardiovascular is a subspecialty within psychophysiology) are not usually concerned with heart activity on Valentine's day. Rather, they are interested in more general issues; for example, whether perceptual accuracy varies with changes in heart activity, or if differential changes in heart rate occur in various emotional states, whether individuals are capable of accurate detection of changes in their own cardiac responses, or if perception of heart rate change can influence the emotion experienced by a person.
Today, we use scientific methods to study changes in heart activity not only during emotional or stressful situations but also in the performance of more subtle tasks, such as signal detection and problem solving. We find that experimental evidence indicates significant interactions of heart activity with somatic (muscle) and central (brain) activity. These findings have been elaborated in the cardiac-somatic concept of Paul Obrist and the intake-rejection formulation of the Laceys, as discussed in chapter 18. In this and the next chapter, changes in heart activity that occur in various behavioral situations are considered. The areas examined in this chapter include such issues as how heart activity varies in infants and children as a function of attentional states and emotion. Questions about relationships between heart activity and speed of response, and as a function of complex motor performance, are explored. Issues regarding cardiovascular response during various cognitive activities are probed (verbal learning, problem solving, and imagery). Also considered are cardiac changes during perception, attention, and orienting reactions.
The next chapter considers heart activity as it relates to emotions, stress, motivation, personality, and social factors. Also included is a discussion of conditioning and interactions between heart and brain. The next section of this chapter reviews the anatomy and physiology of the heart, and how its activity is measured, to enable a better appreciation of the behavioral studies covered in these chapters.