Functional connectivity of secondary visual cortices.

(A) Violin plots show the distributions of functional connectivity (r) of secondary visual cortices (blue) to non-visual sensory-motor areas (purple) and prefrontal cortices (green), averaged across three occipital, PFC, and sensory-motor ROIs (A1 and S1/M1) in sighted adults, blind adults, and infants. Individual dots denote mean connectivity values per participant. Grey trend lines illustrate within-participant changes across sensory–motor and prefrontal targets. Dark-blue horizontal markers indicate group averages. Regions of interest (ROI) displayed on the left. Note that regions extend to ventral surface, not shown. See Supplementary Figure S5 for the full views of three occipital ROIs. (B) Circle plots represent the connectivity of secondary visual cortices to non-visual networks, min-max normalized to [0,1], i.e., as a proportion. OC: occipital cortices; MTH: math-responsive region; LG: language-responsive region; EF: executive function-responsive (response-conflict) region. Asterisks (*) denote significant Bonferroni-corrected pairwise comparisons (p < .05).

Functional connectivity of primary visual cortices (V1).

Violin plots show the distributions of functional connectivity (r) of V1 to non-visual sensory-motor areas (purple) and prefrontal cortices (green), averaged across three PFC ROIs and sensory-motor ROIs (S1/M1 and A1). In sighted adults, blind adults, and infants. Individual dots denote mean connectivity values per participant. Grey trend lines illustrate within-participant changes across sensory–motor and prefrontal targets. Dark-blue horizontal markers indicate group averages. Asterisks (*) denote significant Bonferroni-corrected pairwise comparisons (p < .05). Cross (†) denote marginal difference in Bonferroni-corrected pairwise comparisons (0.05< p <0.1).

Within hemisphere vs. between hemisphere functional connectivity.

Bar graph shows within hemisphere (blue) and between hemisphere (orange) functional connectivity (r coefficient of resting state correlations) of secondary visual (left) and V1 (right) to prefrontal cortices in sighted adults, blind adults, and infants. Blind adults show a larger difference than any of the other groups. Asterisks (*) denote significant Bonferroni-corrected pairwise comparisons (p < .05).

Occipito-frontal functional connectivity.

Bar graph shows across functional connectivity of different sub-regions of prefrontal (PFC) and occipital cortex (OCC) in sighted adults, blind adults, and infants. Sub-regions (regions of interest) were defined based on task-based responses in a separate dataset of sighted (frontal) and blind (frontal and occipital) adults (Kanjlia et al., 2016, 2021; Lane et al., 2015). PFC/OCC-MATH: math-responsive regions were more active when solving math equations than comprehending sentences. PFC/OC-LANG: language-responsive regions were more active when comprehending sentences than solving math equations (Kanjlia et al., 2016, 2021; Lane et al., 2015). In blind adults these regions show biases in connectivity related to their function i.e., language-responsive PFC is more correlated with language responsive OCC. No such pattern is observed in infants. Asterisks (*) denote significant Bonferroni-corrected pairwise comparisons (p < .05). See Supplementary Figure S9 for connectivity matrix.