Exposure of baboons to combined 60 Hz electric and magnetic fields does not produce work stoppage or affect operant performance on a match‐to‐sample task

We examined the effects of combined 60 Hz electric and magnetic field (EMF) exposure on performance of delayed match‐to‐sample (MTS) procedure involving the flash rate of a light as the stimulus. Six baboons ( Papio cynocephalus ) fully acquired the task; four others functioned accurately only when cued. All ten subjects were assigned to EMF‐exposed or sham‐exposed groups of five and were used to test for a work‐stoppage effect that was previously observed with initial exposure to electric fields (EF) of 30 or 60 kV/m. Here, we report the results of two experiments, each consisting of 6 week preexposure, exposure, and postexposure periods. We found no evidence of work stoppage with fields of 6 kV/m and 50 μT (0.5 G) or with 30 kV/m and 100 μT (1.0 G). In neither experiment was there evidence of an adverse effect of 60 Hz EMF exposure on MTS performance. © 1995 Wiley‐Liss, Inc.