Blood Pressure and Avoidance Conditioning

Seven adolescent rhesus monkeys were subjected to four different shock-avoidance schedules; blood pressure and pulse rate were recorded hourly through implanted arterial catheters during a control period and during 15 days of avoidance conditioning. Three additional catheterized monkeys served as controls. Pressures and pulse rates for all 7 experimental monkeys rose significantly during the first day of the schedule. Arterial pressure of 4 animals working on a 6-hr. on-6-hr. off 20-sec. Sidman avoidance schedule then returned to control levels while that of the 3 animals working on longer or more complex schedules remained significantly higher for longer periods of time. In general, when pressures were elevated they remained high throughout the day, rather than just during the hours on schedule, and the variability of these measurements did not change from control values.