Effects of Aging on Cancellation Tasks

University Of Alabama At Birmingham, Birmingham AL

Investigators

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Abstract

Age-related cognitive decline may affect functional independence. Visual search tasks can predict accidents in the elderly. However, most visual search studies in aging rely on brief stimulus presentations and speeded manual responses. It is therefore unclear whether such conditions may reflect the cognitive, sensory, or motor processes involved in other real-life spatial search tasks, particularly where stimuli are visible for extended periods and speeded responses are not required. Cancellation tests usually require manually marking multiple targets in a display while ignoring distractors. Speeded responses are not strictly required, and stimuli may be visible indefinitely. Such tests can be used to assess speed of processing and spatial attention. Cancellation tests are usually given to brain injured subjects. However, recent studies indicate they also may be sensitive to search processes in aging. The aim of this study is to determine whether new methods of cancellation assessment can improve the test's sensitivity to age-related changes in spatial search. The cancellation test will be presented on an interactive touchscreen display. Subjects will touch all targets in random-array cancellation tests with a stylus. Depending on the test, targets when touched will either (1) be marked, (2) disappear, or (3) show no visible change at all. These modifications will model different outcomes of visuomanual exploration of the environment. The display device will calculate (1) number of targets touched, (2) speed of processing, (3) organization of search (through total pathway intersections), and (4) perseverated target contacts. Through assessing whether changes in test format affect these measures, we will determine whether the cancellation test's sensitivity to age-related changes in spatial search may be improved. The findings will provide normative data for future research to determine whether cancellation tests may be sensitive to functional decline in aging and neurologic disorders.