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Biomedical subjects

P C van Wolffelaar

Publications and source records attributed to P C van Wolffelaar.

2 recordsLinked to original sources

Age differences in divided attention in a simulated driving task.

The ability of young, middle-aged, and old adults to divide attention was examined using a dual task experiment involving two continuous performance tasks. The first task was a compensatory tracking task modeled after the important everyday activity of car driving. The second task was a self-paced visual choice-reaction time task requiring analysis of a small visual display presented in such a way that no eye movements were required when the two tasks had to be performed simultaneously. Single-task difficulty was individually adjusted for each subject. Performance-Operating-Characteristics were used to control for individual differences in attention allocation strategies. Even when individual differences in single task performance were adequately controlled for, elderly adults showed a significantly decreased ability to divide attention when compared with young and middle-aged adults. Young and middle-aged adults did not differ in the ability to divide attention.

Adult↗

Sustained attention and sustained effort after closed head injury: detection and 0.10 Hz heart rate variability in a low event rate vigilance task.

In closed head injury patients impaired sustained attention has been used to explain poor performance of complex tasks. However, this basic capacity was never adequately investigated. We investigated sustained attention in an auditory vigilance task and found no evidence at all for an impairment. With an interval of about three months 8 patients, tested in the first half year after closed head injury, and 8 healthy control subjects were confronted twice with a low event rate vigilance task. This yielded measures of signal detection and response latency. Also the amplitude of 0.10 Hz Heart Rate Variability, a power spectral measure, was calculated to indicate sustained effort. Hypotheses that patients would manifest stronger effects of time-on-task on performance and effort were not supported. Independent of sustained attention patients differed from controls in terms of response latencies and sensitivity of discriminating small differences of loudness especially on the first occasion.

Adolescent↗