![]() ![]() Another between-group difference was the cross-modal connectivity with the occipital cortex. Individuals who were early-onset blind were consistently found to recruit more occipital areas, particularly the primary visual cortex (V1), than their late-onset blind counterparts in non-visual tasks (e.g., Burton et al. A common theme revealed across these studies is the differentiation of involvement of the occipital areas between the two groups. 1999), and auditory spatial processing (Collignon et al. 1997), tactile discrimination (Sadato et al. Previous studies investigating functional differences between early- and late-onset blind individuals include pitch change discrimination (Kujala et al. The findings can shed light on the role of visuospatial function in auditory spatial processing and cross-modal plasticity involving the visual system. The neural processes associated with sound localization were compared between individuals with early- and late-onset blindness. The present study explored the mechanisms behind prior visual experience modulating auditory spatial processing. For instance, the lack of visual input among congenitally blind individuals has been revealed to alter their processing of spatial information resulting in under-development of spatial knowledge (Emier 2004 Rieser et al. Processing of sensory information can be modulated by an individual’s experience in life. Information received by sensory systems needs to be processed and integrated before it can be meaningfully utilized by individuals (Beer et al. The findings support the notion that early-onset blind individuals rely more on the occipital areas as a result of cross-modal plasticity for auditory spatial processing, while late-onset blind individuals rely more on the prefrontal areas which subserve visuospatial working memory. In contrast, the accuracy on sound localization only correlated with BOLD responses in the right middle occipital gyrus among the early-onset counterpart. The BOLD responses in the left superior frontal gyrus were significantly correlated with accuracy on sound localization and visuospatial working memory abilities among the late-onset blind participants. Between-group dissociations, however, were found in the right middle occipital gyrus and left superior frontal gyrus. The results revealed common increases in BOLD responses in the middle occipital gyrus, superior frontal gyrus, precuneus, and precentral gyrus during sound localization for both groups. In addition to sound localization, participants were assessed on visuospatial working memory and general intellectual abilities. ![]() The task required participants to listen to novel “Bat-ears” sounds, analyze the spatial information embedded in the sounds, and specify out of 15 locations where the sound would have been emitted. BOLD responses of early- and late-onset blind participants were captured while performing a sound localization task. This study investigated how prior visual experience would modulate auditory spatial processing among blind individuals. Comparing early- and late-onset blindness in individuals offers a unique model for studying the influence of visual experience on neural processing. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |