A large body of research has investigated various aspects of attention in normal aging and Alzheimers disease (AD). Most of the previous studies have shown that divided attention, the ability to attend to two tasks or stimuli simultaneously, declines in both normal aging and AD. In a recent study of attention, Baddeley, Baddeley, Bucks, and Wilcock (2001) reported findings that contrast with other divided attention research. Specifically, they found no effects of aging on divided attention. Taken in combination with their findings of age and AD effects on other aspects of attention, the authors concluded that age-equivalent results on divided attention tasks support the theory that attentional control should be viewed as a fractionated system. Study 1 considered methodological differences between the divided attention tasks used by Baddeley et al., and the tasks used by researchers who have reported age-related differences. Specifically, the effects of task difficulty on age effects were examined. Young, middle-aged, and older adults were compared on a dual-task procedure that combined a secondary visuomotor task (box joining) with a primary verbal task (month reciting) administered at two levels of difficulty. Results showed a significant Age x Task Difficulty interaction. That is, differences among age groups were proportionately greater in the difficult dual-task condition versus the easy condition, suggesting that age-related declines in divided attention may only be detected if tasks are sufficiently difficult.<p>
Study 2 examined attention in normal aging and AD. Young adults, older adults, and early-stage AD patients were compared on tasks of selective attention, focal attention, and divided attention, with each task administered at two levels of difficulty. Similar Group x Task Difficulty interaction effects were detected for all attentional tasks, a finding which is more consistent with a general-purpose model than a fractionated model of attention. Study 3 considered attentional tasks from a clinical perspective. Specifically, the attentional tasks utilized in Study 2 were examined with respect to their ability to correctly classify individuals with early-stage AD and normal older adults. Findings showed that all attentional tasks successfully discriminated patients from cognitively healthy older adults, with one task of divided attention showing particularly impressive sensitivity and specificity. Findings of the three studies are discussed with regard to their implications for future research and clinical practice.
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-01032009-102408 |
| Date | 26 January 2009 |
| Creators | Corney, Patrick |
| Contributors | Kirk, Andrew, Elias, Lorin J., Crossley, Margaret, Campbell, J. I. D. (Jamie), McDowd, Joan |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-01032009-102408/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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