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Visual Cortex Alterations in Early and Late Blind Subjects During Tactile Perception
A Ankeeta1, S Senthil Kumaran1, Rohit Saxena1
128730All India Institute of Medical Sciences, India.
Perception
|February 17, 2021
Summary
Early blind (EB) and late blind (LB) individuals show distinct brain activity during tactile tasks. EB subjects exhibit greater functional connectivity in sensory and attention networks, suggesting unique cross-modal reorganization in the visual cortex.
Area of Science:
- Neuroscience
- Neuroimaging
- Sensory processing
Background:
- The visual cortex's role in tactile perception differs between early blind (EB) and late blind (LB) individuals.
- Understanding cross-modal plasticity in blindness is crucial for sensory rehabilitation.
Purpose of the Study:
- To investigate differences in sensory-motor networks during tactile tasks in EB and LB children and adolescents.
- To explore how the age of blindness onset impacts brain reorganization.
Main Methods:
- Functional magnetic resonance imaging (fMRI) was used to analyze blood oxygen level dependent (BOLD) activity and functional connectivity (FC).
- Participants included 40 EB subjects, 40 LB subjects, and 30 sighted controls, divided into children and adolescent subgroups.
- Statistical analyses included correlation and post hoc tests for multiple comparisons.
Main Results:
- Early blind subjects showed increased functional connectivity between the visual cortex and dorsal attention/sensory-motor networks during tactile tasks.
- Early blind adolescents displayed enhanced connectivity with default mode and salience networks compared to late blind individuals.
- Functional changes correlated with the duration of tactile training, indicating improved performance in EB individuals.
Conclusions:
- Age of blindness onset significantly influences cross-modal reorganization in the visual cortex.
- Early blindness leads to distinct patterns of sensory and visual network alterations compared to late blindness.
- Tactile training duration is associated with functional network changes in both EB and LB individuals.
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