A common metaphor for visual attention is the spotlight (Posner, 1980). It follows from the spotlight metaphor and other similar models (e.g., zoom-lens model; Eriksen and Yeh, 1985) that attention can, according to task-demands, be constricted into a focused beam (i.e., analogous to selective attention) or dilated to encompass a larger breadth (i.e., analogous to divided attention). It is currently unclear how variations in perceptual load of a display affect the FFOV. Lavie (1995; Lavie et al., 2004) proposed that the critical determinant of selective attention (i.e., a constriction of the FFOV) was the perceptual load imposed by the taskselective attention is a necessary outcome of limited perceptual processing capacity. Age-related differences in perceptual processing capacity (e.g., Maylor and Lavie, 1998) may then explain observed age-related differences in FFOV size (e.g., Ball, Beard, Roenker, Miller, and Griggs, 1988). The current study examined how perceptual load and aging affected the FFOV. Younger and older participants viewed brief displays in which they engaged in two tasks: the first task was a perceptual load manipulation, while the second task was a measure of the FFOV. Multiple measures of peripheral task performance suggest that the size of the FFOV for older adults was significantly reduced by increasing perceptual load and this effect of load was greater with increasing distance from fixation. As predicted from the perceptual load model, when perceptual load of the task increased, perceptual sensitivity for the distant peripheral task decreased for older adults. This decrease was greater when the task was farther from fixationindicative of a shrinking spotlight. However, for younger adults, increasing load did not affect peripheral task performance. This age-related difference may be attributable to older adults reduced perceptual processing capacity. The current results support the notion that older adults reduced perceptual processing capacity may be one cause of their reduced FFOV. Limitations of the current study as well as future research are discussed.

Reception and processing of visual information in traffic Mgr. Dana Černochová Abstract The theoretical part of this work deals with the visual perception of the driver. Special attention is paid to the perception of visual information in the whole range of the field of view. From psychological point of view, the term functional field of view is important, the construct taking into account not only perception, but also the attention. Its size depends on the amount of information which have to be processed at any given moment. Foreign literature uses the term "Useful field of view" under the abbreviation UFOV, german literature uses the term "nutzbares Sehfeld" under the abbreviation NSF. The experimental part of the work focuses on evaluating the changes of the visual perception in the range of the visual field in relation to age. For this the SET of 1361 people in age group from 18 to 90 years. In further subchapters the experiment is described where the secondary task was used as variable in order to find out whether the increased cognitive load affects the range of the useful field of view. For this experiment, the set of 645 people of age 18-90 years was used. The parameters of the visual perception in the situations with and without added secondary task were also monitored for the relationship to the...