Effects of Visual and Conversation Loads on Functional Visual Field on a Dynamic Background

The effects of performing a visual task and/or conversation task on a functional visual field (FVF) on a dynamic background simulating a driving situation were experimentally studied. A red or pink circular target was briefly presented somewhere on a movie scene depicting driver's view, and the observer's task was to indicate the target's position. The visual task loaded on the observer was to read out two alphabet letters presented at the center of the visual field. The conversation task was to answer to an easy question orally. The FVF narrowed with the visual task as well as with the conversation task, while it markedly shrunk when both visual and conversation tasks were imposed simultaneously.