Sensory substitution reveals a manipulation bias

Abstract

Sensory substitution is a promising therapeutic approach for replacing a missing or diseased sensory organ by translating inaccessible information into another sensory modality. What aspects of substitution are important such that subjects accept an artificial sense and that it benefits their voluntary action repertoire? To obtain an evolutionary perspective on affective valence implied in sensory substitution, we introduce an animal model of deaf songbirds. As a substitute of auditory feedback, we provide binary visual feedback. Deaf birds respond appetitively to song-contingent visual stimuli, they skillfully adapt their songs to increase the rate of visual stimuli, showing that auditory feedback is not required for making targeted changes to a vocal repertoire. We find that visually instructed song learning is basal-ganglia dependent. Because hearing birds respond aversively to the same visual stimuli, sensory substitution reveals a bias for actions that elicit feedback to meet animals manipulation drive, which has implications beyond rehabilitation.