Visual Attention and Cognition Evidence for scanpaths in hemianopic patients shown through string editing methods.
Zangemeister WH, U Oechsner: Advances in Psychology 1996; 116: 197-22
In continuation of earlier studies, we recorded gaze movements in patients with hemianopic visual field defects primarily due to stroke. Use of high resolution infrared oculography enabled us to record and analyse a variety of tasks including paradigms of visual search, reading and scanpath eye movements. The tasks were recorded several times in sequential order. By applying string-editing methods to the problem of quantitatively analysing search- and scanpaths of the half-blind patients in comparison to healthy subjects, we were able to observe short term adaptation: I.e., training effects of eye movement strategies to improve the initially deficient result on the side of the blind hemifield with respect to the relative difficulty of the specific task. This quantitative and statistically confirmed finding adds new evidence for the top-down control of the human scanpath even in hemianopic patients.