Examining the role of central and peripheral vision in expert decision-making

Abstract

Information pick-up from peripheral vision is thought to play an important role in dynamic decision-making; however, this has not been verified empirically. This thesis reports a series of experiments that used a gaze-contingent manipulation of video footage to examine the role of central and peripheral vision in expert decision-making in the dynamic sport of basketball. In Experiment 1, opaque (black) occlusion was selectively applied to the central and/or peripheral vision of skilled and novice basketball players using a real-time gaze-contingent display. The skilled players made better decisions irrespective of whether they were using central vision, peripheral vision, or the full visual field. However, the opaque occlusion in this task could have concurrently impaired both information pick-up and the guidance of subsequent eye movements. In Experiment 2, occlusion was achieved via visual blur rather than black opaque occlusion in an effort to constrain information pick-up while permitting the guidance of normal visual search. The results again showed that skilled players had consistently higher response accuracy irrespective of the area of visual field they used or the level of blur applied. However, as the expert advantage remained strongly robust even under highly impaired viewing conditions, the question arose as to whether the response slide itself may have contained information that could support expert decision-making performance. Experiment 3 confirmed this suspicion and in Experiment 4 a suitable response mode that contained no inherent information was identified and validated. Experiment 5 adopted this revised response mode to essentially replicate Experiment 2 while also introducing further combinations of central and peripheral blur. Experiment 5 confirmed that skilled players demonstrate higher decision-making accuracy irrespective of the area of the visual field they rely on. Even low levels of blur, despite not influencing decision-making performance, were found to alter the pattern of eye movements used. This suggests that performance is maintained despite measurable changes in gaze. Remarkably, the decision-making performance of the novice participants improved when certain levels of blur were applied to the peripheral visual field. As a consequence, Experiment 6 examined whether the decision-making skill of inexperienced players could be enhanced through training when viewing with gaze-contingent blur. It was found that perceptual training with clear central + blurred peripheral vision led to better performance than equivalent training with normal (full-field) vision or with blurred central + clear peripheral vision. The improvements in performance were independent of changes in visual search strategy, suggesting that alterations in attentional allocation may have been responsible for the training effect. Collectively, the results of the experimental series lead to the conclusion that the ability to interpret information is the critical limiting factor to skilled decision-making rather than the location of the information within the visual field or the pattern of visual search. The findings provide a basis for the development of methodological guidelines for the use of gaze-contingent displays in dynamic tasks and lead to enhanced approaches in the investigation and training of decision-making skill.