Mice were trained to escape from or to avoid 2.45 GHz continuous wave (CW) microwave exposure by emitting an operant response (the response consisted of an animal's interruption of a light beam). If a mouse responded while microwaves were on, irradiation was terminated and remained off for 12 seconds (an escape response). If a mouse responded during the off period, each response (constituting avoidance) would reset a timer that delayed the onset of microwaves for another 12 seconds. During the experimental session a 2900 Hz tone was paired with the microwave exposure. Each animal was tested following administration of each of three psychoactive compounds at varying dosages: chlordiazepoxide, d-amphetamine, and chlorpromazine.
Chlordiazepoxide resulted in a reduced percentage of avoidance responding coupled with an increased percentage of escape responding. The data based on administration of chlorpromazine and of d-amphetamine were highly variable both within and among subjects.