Abstract
Visual experience plays an important role in the development of the visual cortex; however, recent functional imaging studies have shown that the functional organization is preserved in several higher-tier visual areas in congenitally blind subjects, indicating that maturation of visual areas depend unequally on visual experience. In this study, we aim to validate this hypothesis using a multimodality MRI approach. We found increased cortical thickness in the congenitally blind was present in the early visual areas and absent in the higher-tier ones, suggesting that the structural development of the visual cortex depends hierarchically on visual experience. In congenitally blind subjects, the decreased resting-state functional connectivity with the primary somatosensory cortex was more prominent in the early visual areas than in the higher-tier ones and were more pronounced in the ventral stream than in the dorsal one, suggesting that the development of functional organization of the visual cortex also depends differently on visual experience. Moreover, congenitally blind subjects showed normal or increased functional connectivity between ipsilateral higher-tier and early visual areas, suggesting an indirect corticocortical pathway through which somatosenroy information can reach the early visual areas. These findings support our hypothesis that the development of visual areas depends differently on visual experience.
Highlights
Visual deprivation is an idea model to investigate how visual cortex is reorganized to ‘perceive’ the outside world
region of interest (ROI)-based cortical thickness analyses To further elucidate the specific change in cortical thickness of each visual area, we extracted the mean cortical thickness of each visual area in each subject based on the Human PALS-12 atlas (Fig. 2D)
ROI-based resting-state functional connectivity (rsFC) analysis within the visual areas We investigated the rsFC between each pair of the visual areas and found significantly increased rsFC (P,0.05, Bonferroni corrected) between the early visual areas (V1 and V2) and several higher-tier visual areas (V8 and LO) in the same hemisphere in Congenitally blind (CB) subjects (Fig. 5)
Summary
Visual deprivation is an idea model to investigate how visual cortex is reorganized to ‘perceive’ the outside world. Converging evidence suggests that both the early and higher-tier visual areas in CB subjects are activated during performing a variety of tactile or auditory tasks [15,16] These findings indicate that visual experience plays an important role in shaping the structural and functional organization of the visual cortex during the process of development. Increasing evidence has confirmed that CB subjects preserved functional organization in several higher-tier visual areas when performing non-visual sensory task, such as the dorsal stream specialized for spatial processing [25,26] and action control [27], the ventral stream for reading [28] and object recognition [21,29,30], and the MT+ for motion processing [23,31,32,33,34]. The extent and magnitude of the activation of the recruited areas differed between sighted control (SC) and CB individuals [21,23], the co-activation of the higher-tier visual cortex by non-visual sensory inputs in SC and CB highly indicates that the development of at least parts of their functional organization does not require visual experience [42,43]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
