Computer-Based Operant Behavioral System for Microwave Bioeffects Research

For the investigation of the interaction of microwave radiation (MWR) with physiologic processes, a means of exposing a large number of animals to uniform and quantifiable MWR dose rates is desired. The design and characteristics of such a system for operant behavioral studies using rats is described. Individual irradiation chambers composed of probe terminated waveguide sections operating at 1.3 GHz are used. All of the 16 active chambers are driven in parallel from a single source via a modulation insensitive hybrid power divider. An additional group of 16 nonenergized chambers provide for parallel controls. Each of the chambers includes provision for presentation of visual discriminative stimulus, detection of operant response, and delivery of food reward. These behavioral components are managed by an 8 bit microprocessor that provides the necessary speed, reliability, and flexibility at low per unit cost. The input/output interface is described briefly and a typical program flow diagram for schedule controiled conditioning sessions is given. The irradiation/behavioral system represents a novel approach to the study of microwave induced alterations in operant behavior and demonstrates the practicability of adapting inexpensive microprocessor components to the management of large operant behavioral systems.