An increase in a virtual hemianopic field defect enhances the efficiency of secondary adaptive gaze strategies

Zangemeister WH, Utz P . Current Psychology of Cognition 2002; 21: 281-303

We report findings about search and scanpath eye movements (EMs) in normal healthy subjects that had to deal with a virtual homonymous hemianopia (VHH) that compared exactly to the deficit of patients with stable full homonymous hemianopia.We posed three questions: 1.Does a sensory-motor adaptation occur in these VHH patients? 2. Is it possible to enhance the effect of this adaptation through training by enlargement of the 50% field defect towards the seeing side? 3. How large is the additional effect of training. Our healthy subjects responded to VHH quite similarly as hemianopic patients: the training of parafoveal eccentric viewing of up to 10° together with specific advice to improve saccadic strategies helped the adaptation of VHH subjects significantly, and improved their gaze efficiency by becoming faster and more accurate.