Reduced Dynamic Interactions Within Intrinsic Functional Brain Networks in Early Blind Patients.

Xianglin Li,Zhenbo Sun,Jie Tian,Bin Wang,Jikai Xia,Ming Zhang,Peiyuan Wang,Ailing Wang,Junhai Xu

doi:10.3389/fnins.2019.00268

Abstract

Neuroimaging studies in early blind (EB) patients have shown altered connections or brain networks. However, it remains unclear how the causal relationships are disrupted within intrinsic brain networks. In our study, we used spectral dynamic causal modeling (DCM) to estimate the causal interactions using resting-state data in a group of 20 EB patients and 20 healthy controls (HC). Coupling parameters in specific regions were estimated, including the medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and inferior parietal lobule (IPC) in the default mode network (DMN); dorsal anterior cingulate cortex (dACC) and bilateral anterior insulae (AI) in the salience network (SN), and bilateral frontal eye fields (FEF) and superior parietal lobes (SPL) within the dorsal attention network (DAN). Statistical analyses found that all endogenous connections and the connections from the mPFC to bilateral IPCs in EB patients were significantly reduced within the DMN, and the effective connectivity from the PCC and lIPC to the mPFC, and from the mPFC to the PCC were enhanced. For the SN, all significant connections in EB patients were significantly decreased, except the intrinsic right AI connections. Within the DAN, more significant effective connections were observed to be reduced between the EB and HC groups, while only the connections from the right SPL to the left SPL and the intrinsic connection in the left SPL were significantly enhanced. Furthermore, discovery of more decreased effective connections in the EB subjects suggested that the disrupted causal interactions between specific regions are responsive to the compensatory brain plasticity in early deprivation.

Highlights

The recognition of objects could be manipulated through the coordinated cross-modal interactions of different modalities, such as vision, touch and audition (Amedi et al, 2005; Dormal et al, 2018)
Fortyone independent components were generated according to the minimum description length criteria (MDL) criterion, and the generated components were sorted by their correlations with the default mode network (DMN), salience network (SN), and dorsal attention network (DAN) templates
Based on the group ICA analysis, four Region of Interest (ROI) were defined for DMN, including the medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), bilateral IPC; three ROIs for SN: dorsal anterior cingulate cortex (dACC), left anterior (lAI), and right anterior insulae (rAI), and four bilateral ROIs for DAN: lEFF, rFEF, lSPL, and rSPL

Summary

Introduction

The recognition of objects could be manipulated through the coordinated cross-modal interactions of different modalities, such as vision, touch and audition (Amedi et al, 2005; Dormal et al, 2018). Deprivation of one sensory modality could give us a chance to explore the plasticity changes of the cognitive functions (Jiang et al, 2015). The other hypothesis is based on the compensatory explanation, in which the blind patients exhibit a superior ability in retained sensory modalities (PascualLeone et al, 2005). EB patients exhibit disrupted functional connections and stronger parietal and auditory networks compared with sighted subjects (Boldt et al, 2014; Hou et al, 2017; Abboud and Cohen, 2019). EB patients showed a compensatory pattern in the primary sensory networks, while the other brain networks related to cognition might be disrupted due to the early deprivation

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