Poster B16, Tuesday, August 20, 2019, 3:15 – 5:00 pm, Restaurant Hall
Congenital blind causes the functional connectivity plasticity of the right inferior parietal lobe in number processing
Runhua Guo1, Suting Feng1, Mingyang Li1, Linjun Zhang2, Ke Wang1, Zaizhu Han1;1Beijing Normal University, 2Beijing Language and Culture University
Number processing relies heavily on the inferior parietal lobe (IPL) in healthy people. The processing has also been found to depend on the connections between the IPL and primary sensory cortices (i.e., occipital lobe) in the blinds (Kanjlia et al., 2016). It remains unclear whether the congenital blindness causes the increased connectivity of other high-level cerebral regions in addition to primary perception cortices. To address this issue, we recruited 22 congenitally blind adults (CB) and 21 sighted controls (SC). We collected their resting-state functional magnetic resonance imaging (rs-fMRI) data and performance in number (e.g., numerical associative matching), language (e.g., word associative matching, lexical decision) and primary perception tasks (e.g., primary figure discrimination). The CBs were behaviorally tested with auditory and tactile input modalities, whereas the SCs were with visual and auditory ones. We first separately constructed the functional networks of each of two subject groups using rs-fMRI data. Also we compared the degree value of each voxel in the network (i.e., the sum of the functional connection strength of the voxel with other voxels in the whole brain) between the two groups. We observed three regions whose degree values were higher in the blind than the sighted: bilateral IPLs and left superior parietal lobe. More importantly, the activation intensity of the right IPL (rIPL) (measured by the area’s regional amplitude of spontaneous low-frequency fluctuations, ALFF) was significantly correlated with the performance of number processing in the blind of both auditory and tactile modalities, and in the sighted of visual but not auditory modality. Then, we compared the connectivity strength of each functional connection liking with the rIPL in the network between the two groups. The blindness led to the stronger connectivity of the rIPL with two primary perception areas (the right lingual gyrus, the right middle occipital), and three high-level processing areas (bilateral middle temporal poles, the left middle cingulate cortex). Of the regions, the ALFF values of the right lingual gyrus, and bilateral middle temporal poles were significantly correlated with the performance of number processing. It demonstrates that the blindness results in connection strength enhancement of the rIPL with both primary perception and high-level processing regions for number processing. These findings refine how the absence of visual experience modulates the cortical network of number processing, in which the rIPL, as a key node, strengthens the connectivity with the primary and high-level cortices.
Themes: Development, Multisensory or Sensorimotor Integration
Method: Functional Imaging