Properties of cross-modal occipital responses in early blindness: An ALE meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and coordinate-based meta-analysis of observational neuroimaging studies
PubMed 31677587 · doi:10.1016/j.nicl.2019.102041
What was done
Following PRISMA guidelines, the authors conducted an activation likelihood estimation coordinate-based meta-analysis across 55 neuroimaging studies. They evaluated distinct brain regions involved in object, spatial/motion, and language processing, as well as shared regions across auditory and tactile modalities, in individuals with early blindness.
What was found
The abstract reports qualitative anatomical patterns without statistical values or coordinate metrics. Spatial processing consistently recruited the dorsal fronto-parietal network, object processing recruited the ventral occipito-temporal network, and contrast analyses showed specific activation in the left cuneus and lingual gyrus for language processing. Conjunction analyses identified common auditory and tactile activations in the right middle temporal gyrus, right precuneus, and a left parieto-occipital region.
Why it matters
This study shows that cross-modal visual cortex recruitment in early blindness is functional-domain-dependent rather than sensory-modality-dependent, indicating preserved stream specialization and reverse hierarchical organization for language.
Limits
The abstract does not report the total participant count across the 55 included studies, effect sizes, statistical thresholds, or heterogeneity measures. Coordinate-based meta-analyses rely on published peak coordinates rather than raw neuroimaging datasets, and findings in early blindness cannot be generalized to late-onset blindness.