[Directed forgetting in rats using the radial arm maze].

The present experiments investigated whether rats could selectively retain the necessary spatial information and forget the unnecessary one in the radial arm maze task. In Experiment 1, rats were trained in a directed forgetting preparation in which the test choice was made following the R-cue and not following the F-cue. The performance on the probe tests, in which the test choice runs were given following the F-cue, was not affected by the F-cue and it was the same as on the R-cued trials. In Experiment 2, rats were trained in an intertrial-interference preparation in which R-cued and F-cued forced choices were run successively in a random order. In the test choice, rats obtained reinforcers if they avoided the R-cued arms. The analyses of performance of the test choices revealed that rats didn't utilize these instructional cues and consistently adopted a win-shift strategy. These findings suggest that the performance of the rats in the radial arm maze is highly inflexible.