Effect of relevance shifts in category acquisition: a test of neural networks

The effect of changing the validity of stimulus dimensions in the course of category learning was investigated. Contrary to previous experiments on interdimensional relevance shifts, a family resemblance stimulus structure was used that allowed for the direct comparison of performance on items learned before and after the relevance shift. In both experiments, the test performance was dominated by information that was acquired after the relevance shift. The results indicate that the acquired knowledge of the 2 learning phases was not integrated, but knowledge learned before the shift was partly replaced by information acquired after the shift. Simulation of the results by the independent cue model, the configural cue model, and ALCOVE (attention learning covering map) demonstrates that these models must be expanded by a mechanism that inhibits the integration of information acquired before and after the relevance shift.