State-dependent modulation of functional connectivity in early blind individuals

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Resting-state functional connectivity (RSFC) studies indicate visual deprivation impacts brain functional architecture.
• Early blind (EB) individuals show reduced occipito-temporal RSFC at rest but enhanced activation during auditory tasks.
• A discrepancy exists between resting-state and task-dependent findings in EB occipito-temporal connectivity.

Purpose of the Study:

• To directly compare functional coupling between temporal and occipital networks at rest and during an auditory task in EB and sighted controls (SC).
• To investigate how cognitive state differentially influences brain connectivity in EB and SC populations.
• To reconcile apparent discrepancies between prior RSFC and task-based studies in visual deprivation.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) to assess brain activity.
• Compared resting-state functional connectivity (RSFC) with task-dependent functional connectivity during an auditory task.
• Defined shared functional brain clusters across groups (EB and SC) and cognitive states (rest and auditory task).

Main Results:

• In EB individuals, occipito-temporal correlations were higher during the auditory task than at rest.
• In SC individuals, the opposite pattern was observed: higher correlations at rest than during the task.
• EB individuals exhibited higher temporal variability in occipito-temporal RSFC, suggesting occipital regions function as a multiple demand system.

Conclusions:

• Cognitive state significantly and differentially influences the connectivity profiles of EB and SC individuals.
• Findings bridge the gap between previous task-dependent and RSFC studies in visual deprivation.
• Relying solely on resting-state data for group-difference inferences in functional brain architecture requires caution.