Biomedical subjects

Joan M McDowd

Publications and source records attributed to Joan M McDowd.

4 recordsLinked to original sources

PubMed2006

Task switching after stroke.

BACKGROUND AND PURPOSE: Task switching is a cognitive skill that may be compromised after brain damage. The purposes of this study were to examine task-switching abilities in the subacute phase after stroke, to determine whether a switching task under endogenous or internal control is more difficult than a switching task under exogenous or cued control, and to determine whether deficits in switching attenuate in the first few months after stroke. SUBJECTS: The participants in this study were 46 adults with stroke and 38 adults without stroke. METHODS: Subjects performed 2 computer-based switching tasks, an alternating task that relied on endogenous control and a cued task that relied on exogenous control. Testing was done in subjects' homes at 1 and 3 months after stroke and at a 2-month interval for control subjects. Switch costs, or the difference between the no-switch condition and the switch condition, were calculated for accuracy and response time. RESULTS: Subjects in the stroke group had higher switch costs for accuracy than did subjects in the control group. The alternating task was more difficult than the cued task, with higher switch costs for accuracy and response time. The alternating task was particularly difficult for subjects in the stroke group, with high switch costs for accuracy. Both groups showed decreased response time switch costs at the second testing session. DISCUSSION AND CONCLUSION: Task switching, particularly if under endogenous control, is impaired in adults in the subacute phase after stroke. Clinicians should be aware of performance deficits that may relate to task switching.

Aged↗

PubMed2005

The role of visual attention in predicting driving impairment in older adults.

This study evaluated the role of visual attention (as measured by the DriverScan change detection task and the Useful Field of View Test [UFOV]) in the prediction of driving impairment in 155 adults between the ages of 63 and 87. In contrast to previous research, participants were not oversampled for visual impairment or history of automobile accidents. Although a history of automobile accidents within the past 3 years could not be predicted using any variable, driving performance in a low-fidelity simulator could be significantly predicted by performance in the change detection task and by the divided and selection attention subtests of the UFOV in structural equation models. The sensitivity and specificity of each measure in identifying at-risk drivers were also evaluated with receiver operating characteristic curves.

Age Factors↗

PubMed2003

Attentional abilities and functional outcomes following stroke.

Although stroke affects cognitive functioning as well as motor functioning, research on cognitive consequences has lagged behind that focused on motor function. The evidence that is accruing suggests that cognitive function is importantly related to successful rehabilitation. The present study examined two aspects of attentional functioning (divided attention and switching attention) in older adult stroke survivors and healthy older adults. In addition, the authors investigated the relation between attention and functional outcomes following stroke. Results revealed stroke-related deficits in both of the types of attention as well as significant associations between attentional functioning and both physical and social outcome measures. Poorer attentional performance was associated with a more negative impact of stroke on daily functioning. These findings suggest an important role for attention in post-stroke function and provide information that can contribute to improving outcomes following stroke.

Aged↗

PubMed1988

Effects of aging and task difficulty on divided attention performance.

We report two experiments that compare the performance of young and older adults on perceptual-motor tasks involving division of attention. Previous studies have shown older people to be especially penalized by divided attention situations, but the generality of this finding was recently challenged by Somberg and Salthouse (1982). The present study was conducted to investigate the possibility that age differences in dual-task performance are amplified by an increase in the difficulty of the constituent tasks, where difficulty was manipulated by varying the central, cognitive nature of the tasks (Experiment 1) or the degree of choice involved (Experiment 2). With the present tasks, strong evidence was found for an age-related decrement in divided attention performance. Contrary to our original expectations, however, it does not seem that division of attention presents some especial difficulty to older people. Rather, division of attention is one of several equivalent ways to increase overall task complexity. In turn, age differences are exaggerated as tasks are made more complex.

Adult↗