Skilled visual‐motor performance by monkeys in a 1.2‐GHz microwave field

Abstract

Three young adult rhesus monkeys (Macaco mulatto) were exposed to radio‐frequency electromagnetic radiation (RFR) at average power densities of 10 and 20 mW cm−2, which resulted in respective SARs of 0.8 and 1.6 W Kg−1. Exposure sessions took place at two‐day intervals until completion of three 120‐minute exposures at each power level; 1.2‐GHz continuous‐wave (CW) irradiation was centered on a subject's head with the E‐field vector parallel to the horizontal plane of the cranium. The monkeys performed a compensatory visual‐tracking task with alternating periods of work and rest of 1.5‐minute duration before and during exposure to radiation. During a work period, the task required continuous visual vigilance and skilled motor performance. The animals were motivated by mild electrical stimulation to maintain a circular cursor within the center 15% of an oscilloscopic display. The cursor was driven off this safe on‐target area by a complex sinusoidal track that covered 40% of the display. Control data were used to establish 95% simultaneous confidence limits for the adjusted root mean square (ARMS) of tracking errors. The ARMS values from exposure sessions showed no decrement relative to control data. It is concluded that the exposures at 10 and 20 mW cm−2 did not have deleterious effects upon the skilled performance of a moderately large primate.