Our brain integrates sensory information from multiple senses in order to increase perceptual precision and accuracy. However, this process continuously develops throughout childhood and only reaches adult-like precision gains in late childhood or adolescence. Furthermore, recent research suggests that early sensory experience cross-modally influences perceptual processes in the other senses. For example, the absence of vision in early-blind individuals leads to a decreased accuracy in auditory space representation. At the same time, an increased use of the remaining senses, such as touch and hearing, has been shown to lead to perceptual enhancements in these senses. However, it is not known what role sensory experience plays for the development of multisensory integration. Combining behavioural and electrophysiological measures, this thesis investigates the development of audio-haptic integration in typically sighted individuals and individuals with different degrees of developmental visual experience: early blindness, late blindness, and low vision. Findings demonstrate that optimal audio-haptic integration develops between 13-17years of age in sighted individuals. Furthermore, results suggest that early visual experience is not necessary for the development of this process, but rather delays it. In fact, early blindness leads to alterations in neural processing of audio-haptic integration that reflects a change integration strategy, indicated by a shift from sensory enhancement to sensory inhibition. Furthermore, late-onset blindness leads to an impairment in audio-haptic integration, which is reflected by changes in sensory and perceptual processing. The investigations presented here offer a new perspective on our understanding of perceptual development by recognizing the role of the sensory environment of the developing individual. The present findings highlight the importance of sensory consistency across development, pointing towards a central role of adolescent neural plasticity that can critically affect higher-order multisensory processes later in life. Furthermore, they offer important implications for the development and improvement of sensory rehabilitation approaches for the visually impaired.
|Date of Award||8 Nov 2019|
|Supervisor||Karin Petrini (Supervisor) & Michael Proulx (Supervisor)|
Development of audio-haptic multisensory integration in sighted and non-sighted individuals: (Alternative Format Thesis)
Scheller, M. (Author). 8 Nov 2019
Student thesis: Doctoral Thesis › PhD