6533b834fe1ef96bd129d205

RESEARCH PRODUCT

Wearing glasses to hear differently? Aftereffects of visuomanual prismatic adaptation on auditory perception

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description

Sensorimotor plasticity is defined as the ability to produce an appropriate motor response face to environmental or bodily changes. The classical experimental paradigm to study sensorimotor plasticity is prism adaptation, which consists of pointing to visual targets while wearing prisms that shift the visual field laterally or vertically. Its aftereffects are not restricted to sensorimotor behavior but extend to sensorial modalities not directly involved during prism exposition, such as audition. There exists a mental representation of auditory frequencies in which low auditory frequencies are associated with the left part of space and high auditory frequencies with the right part of space. The first aim of the present thesis work is to study the organization of this mental representation and its modulation after lateral and vertical prism adaptation. The second objective is to explore aftereffects of lateral prism adaptation in auditory divided attention in healthy people. Finally, the third and last purpose, is a clinical one, which aims as assessing aftereffects of prism adaptation on the perception of unilateral tinnitus perception.Regardless the musical expertise, the first study showed the existence of an auditory pseudoneglect directed toward low auditory frequencies within a large auditory spectrum. This initial bias is shifted toward high auditory frequencies after prism adaptation to a leftward optical deviation. The second study investigated the vertical prism adaptation. We showed the first sensorimotor aftereffects after vertical adaptation to both optical deviations, as well as the first modulation of the auditory pseudoneglect after prism adaptation to a downward optical deviation. In the third study, we observed new results with aftereffects of prism adaptation to a leftward optical deviation on auditory divided attention in healthy individuals. Finally, the fourth investigation was a case study which provided preliminary and promising results on the modulation of unilateral tinnitus perception after lateral prism adaptation. Overall, the results of this thesis work testify to crossmodal aftereffects of prism adaptation, specifically in the auditory field. Prism exposure produces changes in pitch perception and auditory attention orientation. Furthermore, although further studies are needed, the observed modulation of tinnitus perception after prism adaptation opens new therapeutic research avenues.