Abstract:
This thesis investigates factors involved in the phenomenon of apparent narrowing of the peripheral visual field with the introduction of a competing foveal task. In the first experiment it is shown that, only when the initial experience of the subject is with an easy foveal task, a more difficult level of the foveal task is accompanied by a deterioration in peripheral detection. The second experiment investigates the significance of manifest anxiety in determining the extent of decline in peripheral detection in the dual-task situation. Manifest anxiety is shown to be non-significant in this respect. The same order effects in peripheral detection trends with the variation of foveal task difficulty, as were found in Experiment I, are also noted in Experiment II, A tentative hypothesis, based on strategy development by the subject for performance in the dual-task situation, is advanced as a source of the order effect observed.