vision loss impact on navigation in virtual reality

Conditions: Stroke, Ischemic; Quadrantanopia; Hemianopsia, Homonymous; Hemianopia, Homonymous; Hemianopia; Hemianopsia; Occipital Lobe Infarct; Visual Field Defect, Peripheral; Vision Loss Partial; Quadrantanopsia; Stroke Hemorrhagic

Summary: the purpose of this research is to better understand the impact of cortically-induced blindness (cb) and the compensatory strategies subjects with this condition may develop on naturalistic behaviors, specifically, driving. using a novel virtual reality (vr) program, the researchers will gather data on steering behavior in a variety of simulated naturalistic environments. through the combined use of computer vision, deep learning, and gaze-contingent manipulations of the visual field, this work will test the central hypothesis that changes to visually guided steering behaviors in cb are a consequence of changes to the visual sampling and processing of task-related motion information (i.e., optic flow).


Eligibility criteria:
cortically blind group: inclusion criteria: * residents of the united states or canada * presence of one-sided stroke or stroke-like damage to primary visual cortex or its immediate afferent white matter sustained within the specified age range of 21 - 75 years (verified by mri and/or ct scans) * reliable visual field defects in both eyes (homonymous defects) as measured by humphrey or equivalent perimetry. * willing, able, and competent to provide their own informed consent * cognitively able, responsible to understand written and oral instructions in english * emmetropic or else wear corrective contact lenses inside the virtual reality headset exclusion criteria: * those who have never driven or earned a drivers' license * past or present ocular disease interfering with visual acuity * best corrected visual acuity (bcva) worse than 20/40 in either eye * sustained damage to the dorsal lateral geniculate nucleus * presence of diffuse, whole-brain degenerative processes * presence of brain damage deemed by study staff to potentially interfere with outcome measures * history of traumatic brain injury * documented history of drug/alcohol abuse * diagnosis of cognitive or seizure disorders * diagnosis of one-sided attentional neglect control group: inclusion criteria: * normal or corrected-to-normal vision, who are between the ages of 21 and 75 years of age, roughly matched to the age of cb subjects enrolled above * competent and responsible, as determined by the principal investigator * willing, able, and competent to provide their own informed consent * normal cognitive abilities, be able to understand written and oral instructions in english * emmetropic or else wear corrective contact lenses inside the virtual reality headset exclusion criteria: * subjects who have never driven or earned a drivers' license * bcva worse than 20/40 in either eye * presence of vision loss from ocular diseases or disorders * presence of a visual field defect * inability to wear corrective contact lenses inside the virtual reality helmet if required to see clearly * subjects with a history of neurological disorders * subjects with a history of tbi * persons who lack the competence or are otherwise unable to perform the visual testing as directed.

Keywords: occipital stroke vision loss after stroke vision recovery vision restoration partial vision loss homonymous quadrantanopsia homonymous quadrantanopia stroke