Early visual cortex is recruited for executive functioning in congenital blindness
Shipra Kanjlia1, Marina Bedny1; 1Johns Hopkins University
Recent evidence has shown that in congenital blindness, visual cortices are repurposed for higher cognitive functions, including language and mathematical reasoning. According to one hypothesis, “visual” cortices are taken over by multiple fronto-parietal networks in blindness. This hypothesis predicts that visual cortices may take on domain general executive functions. We asked whether executive functioning during a stroop task recruits visual regions in congenital blindness and whether these regions are different from those previously shown to respond to math and language. While undergoing fMRI, nineteen congenitally blind (CB) and nine sighted (S) participants judged whether voices of speakers were male or female. On congruent trials, a female speaker said “female” or a male speaker said “male” and vice versa on incongruent trials. On neutral trials, male and female speakers said either “island” or “store.” Domain-general fronto-parietal networks of blind participants responded more during incongruent and congruent trials than neutral trials. An inferior parietal region showed a congruency effect across blind and sighted participants (main effect: F(1,26)=4.64, p=0.04; group interaction: F(1,26)=0.08, p=0.77). In congenitally blind but not sighted individuals, primary visual cortex (V1) responded more to incongruent than congruent trials (CB: F(1,18)=4.52, p=0.04; S: F(1,8)=1.88, p=0.21; group interaction: F(1,26)=5.73, p=0.02). Math-responsive visual regions showed a marginal congruency effect in CB individuals (F(1,18)=3.20, p=0.09). Language-responsive visual regions did not show a congruency effect in CB individuals (LO: F(1,18)=1.69, p=0.21; VOT: F(1,18)=0.17, p=0.68). These results provide further evidence for the hypothesis that visual cortices are repurposed for higher cognitive functions in congenital blindness.
Topic Area: OTHER