The role of learning in sensory-motor modality switching.

Previous research has indicated that modality switching is considerably affected by modality compatibility. It has been shown that switch costs are higher for switching between relatively incompatible sensory-motor modality mappings (i.e., auditory-manual and visual-vocal) compared to switching between compatible mappings (i.e., auditory-vocal and visual-manual). So far, however, it has been unclear whether these findings are influenced by learning processes resulting from very small stimulus sets and a large number of stimulus repetitions. In the present study, we investigated the role of learning concept-to-category associations (Experiment 1) as well as influences of learning concept-to-modality mappings (Experiment 2) on sensory-motor modality switching in semantic categorizations. The results of both experiments revealed shorter overall reaction times due to learning. Additionally, learning of concept-to-category associations (Experiment 1) led to a significant reduction of modality switch costs. Interestingly, however, modality-compatibility effects were neither significantly influenced by learning of concept-to-category associations nor by learning of concept-to-modality mappings. Thus, the present study provides first evidence that learning on the semantic level influences modality switching but it does not significantly affect modality compatibility.