Abstract
About two-thirds of people suffering from mild to moderate traumatic brain injury (mTBI) suffer from some sort of visual disturbance (Goodrich et al., 2013). These patients suffer can suffer from reduced visual acuity and visual field, as well as deficits in visual attention and occulomotor skills. The present study is investigating whether visual attention and oculomotor deficits might be explained by cortical damage from mTBI. Veterans previously diagnosed with traumatic brain injury and combat controls are being recruited for a battery of behavioral tasks aimed at quantifying spatial attention allocation, eye movement accuracy, and motion perception ability. In addition, the fMRI arm of the study targets the frontal eye fields (FEF) and intraparietal sulcus (IPS), cortical regions involved in planning eye movements as well as prioritizing visual attention (Jerde et al, 2012). Because mTBI also impacts integrity of white matter (WM) tracts (Davenport et al., 2012), diffusion weighted imaging is also being used to assess the integrity of WM adjacent to frontal and parietal regions of interest. Of the 14 mTBI patients who have participated in behavioral tests at the time of abstract submission, 9 demonstrated convergence insufficiency (57%), as compared with 2 of 9 (22%) of combat controls. Additionally, mTBI patients with demonstrably normal acuity and convergence performance report double vision during reading and other visual tasks in cluttered environments. The goal of the study is to use fMRI and DTI to identify biomarkers for these oculomotor deficits that arise during visual processing of complex scenes.
Meeting abstract presented at VSS 2016