Structural and functional attention network connectivity in relation to visual selective attention dysfunction in cerebral visual impairment

Abstract

Individuals with cerebral visual impairment (CVI) often demonstrate difficulties with visual selective attention; however, the underlying neural mechanisms remain unclear. In this study, we investigated whether structural and functional connectivity between and within the attention networks, thalamus, and early visual areas is differentially associated with performance on a conjunction search task in participants with CVI as compared to controls. Data from 26 participants was collected and analyzed (10 CVI, four female, 17.4 years, 5.38 s.d., 16 control, 10 female, 22.25 years, 4.25 s.d.). White matter tracts associated with the dorsal and ventral attention networks as well as structural and functional connectivity matrices of the dorsal and ventral attention networks were generated for each participant. Group differences in conjunction search outcomes, tract volume, and network connectivity strength were evaluated. General linear models were used to investigate the relationship between neuroimaging predictor variables and each of the four conjunction search primary outcomes. All analyses were adjusted for age and verbal cognition. In the CVI group impaired visual search was associated with weaker structural and stronger functional connectivity, while in the control group the opposite effect was observed. Together, these results suggest that functional over-recruitment may be a maladaptive compensatory mechanism.

Keywords: cerebral visual impairment (CVI); diffusion tractography; dorsal attention network; selective visual attention; ventral attention network.