Examination of latent inhibition using shuttle-box avoidance task in rats

Abstract

The effects of pre-exposure of conditioned stimuli (CS) on subsequent shuttle-box avoidance learning were examined in rats. Two intensities of tone were used as the CS. The first and second groups were trained using high-and low-intensity CS, respectively, without any CS pre-exposure (control groups). The third group was trained using the low-intensity CS following the pre-exposure of the same CS (unchanged group). The fourth group was also trained using the low-intensity CS, but it had been pre-exposed to the high-intensity CS (decreased group). The final group was trained using the high-intensity CS with the low-intensity CS pre-exposure (increased group). The avoidance learning was retarded in the three experimental groups compared to the control groups (latent inhibition). However, the greatest retardation was shown in the unchanged group, next in the decreased group, and the least in the increased group.