Previous studies have indicated that the useful or functional field of view is a dynamic visual measure. Specifically, it has been shown to constrict as a function of increasing ago, decreasing target duration, decreased conspicuity, and to expand as a function of practice. Two possible explanations for the age-related decline were examined: (1) older observers have a deficit in selective attention which prevents them from ignoring irrelevant information, thereby making a target lees conspicuous, and (2) the time required to process a given visual area increases with age. The purpose of this study was to determine which of these explanations would most likely account for the age -related constriction of the useful field of view.
Four young, five middle-aged, and five older observers were each tested at five brief target durations on two versions of a peripheral localization task: one with distractors and a similar teak without distractors. Both tasks employed a concurrent focal task. All observers were then trained for five consecutive sessions on the same peripheral localization task with distractors, followed by post-training tooting on both tasks. As expected, errors in radial localization performance increased with age and also at greater eccentricities for both tasks. Only the middle-aged observers demonstrated significant improvement on both tasks as a result of practice. Young observers, however, performed so well initially that little room was left for improvement. Conversely, older observers performed poorly before and after training reflecting the age-related difficulty of the tasks. Overall, the results were consistent with the hypothesis that the time required to process a given visual area increases with age.
| Identifer | oai:union.ndltd.org:WKU/oai:digitalcommons.wku.edu:theses-3366 |
| Date | 01 August 1989 |
| Creators | Frey, Francis |
| Publisher | TopSCHOLAR® |
| Source Sets | Western Kentucky University Theses |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Masters Theses & Specialist Projects |
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