Functional Connectivity Density in Congenitally and Late Blind Subjects

Area of Science:

• Neuroscience
• Neuroimaging
• Developmental neuroscience

Background:

• Visual deprivation during development alters brain structure and function.
• The impact of visual deprivation on spontaneous brain functional organization is not well understood.

Purpose of the Study:

• To investigate how visual deprivation at different developmental stages affects the brain's spontaneous functional organization.
• To compare the functional connectivity changes in congenitally blind (CB) and late blind (LB) individuals.

Main Methods:

• Voxel-based functional connectivity density (FCD) analyses were employed.
• Functional brain organization was assessed in sighted controls (SC), CB, and LB individuals.

Main Results:

• Both CB and LB groups showed decreased short- and long-range FCD in the primary visual cortex (V1) and decreased long-range FCD in somatosensory and auditory cortices compared to SC.
• CB individuals exhibited greater increases in short- and long-range FCD within the ventral visual stream and hippocampal complex than LB individuals.
• Short-range FCD in the left V1 positively correlated with the duration of blindness in the LB group.

Conclusions:

• Visual deprivation before the critical developmental period induces more extensive brain functional reorganization than deprivation after this period.
• These findings suggest that early visual deprivation may enhance the brain's capacity for processing non-visual information.