Occasion Setting With Simultaneous Compounds in Rats

Investigated rats' solutions of simultaneous feature positive discriminations (XA+, A-). When X was a visual cue and A was an auditory cue of moderate intensity, the rats solved the discrimination by associating X with the food unconditioned stimulus (US) and ignoring A. But when X was a visual cue and A was a loud auditory cue, the rats solved the discrimination by using X to set the occasion for responding that was based on associations between A and the US. The use of these two strategies was apparently determined by the perceptual (intensity) characteristics of A during learning of the discrimination: It was not affected by A's conditioning history prior to discrimination training, nor by A's intensity during a posttraining test. The results were discussed in terms of recent theories of occasion setting and generalization.