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Biomedical subjects

Gerald Matthews

Publications and source records attributed to Gerald Matthews.

7 recordsLinked to original sources
PubMed2005

Signal regularity and the mindlessness model of vigilance.

Robertson, Manly, Andrade, Baddeley, and Yiend (1997) have proposed that detection failures in vigilance tasks result from a 'mindless' withdrawal of attentional effort from the monitoring assignment. To explore that view, they modified the traditional vigilance task, in which observers make button-press responses to signify the detection of rarely occurring critical signals, to one in which button-press responses acknowledge frequently occurring non-signal events and response withholding signifies signal detection. This modification is designed to promote a mindless withdrawal of attentional effort from the task through routinization. The present study challenges the validity of the mindlessness model by showing that with both types of task, observers utilize subtle patterns in the temporal structure of critical signal appearances to develop expectations about the time course of those appearances that affect performance efficiency. Such expectations enhance performance on the traditional vigilance task, but degrade performance on the modified task.

Adolescent↗
PubMed2004

Effects of sensory modality and task duration on performance, workload, and stress in sustained attention.

The workload and stress associated with a 40-min vigilance task were examined under conditions wherein observers monitored an auditory or a visual display for changes in signal duration. Global workload scores fell in the midrange of the NASA Task Load Index, with scores on the Frustration subscale increasing linearly over time. These effects were unrelated to the sensory modality of signals. However, sensory modality was a significant moderator variable for stress. Observers became more stressed over time as indexed by responses to the Dundee Stress State Questionnaire, with evidence of recovery in the auditory but not the visual condition toward the end of the watch. This result and the finding that signal detection accuracy - although equated for difficulty under alerted conditions - favored the auditory mode, indicate that display modality and time on task should be considered carefully in the design of operations requiring sustained attention in order to enhance performance and reduce stress. Actual or potential applications of this research include domains in which monitoring is a crucial part, such as baggage screening, security operations, medical monitoring, and power plant operations.

Adolescent↗
PubMed2003

The vigilance decrement reflects limitations in effortful attention, not mindlessness.

Robertson, Manly, Andrade, Baddeley, and Yiend (1997) proposed that the decline in performance efficiency over time in vigilance tasks (the vigilance decrement) is characterized by "mindlessness" or a withdrawal of attentional effort from the monitoring assignment. We assessed that proposal using measures of perceived mental workload (NASA-TLX) and stress (Dundee Stress State Questionnaire). Two types of vigilance task were employed: a traditional version, wherein observers made button-press responses to signify detection of rarely occurring critical signals, and a modified version, developed by Robertson et al. to promote mindlessness via routinization, wherein button-press responses acknowledged frequently occurring neutral stimulus events and response withholding signified critical signal detection. The vigilance decrement was observed in both tasks, and both tasks generated equally elevated levels of workload and stress, the latter including cognitions relating to performance adequacy. Vigilance performance seems better characterized by effortful attention (mindfulness) than by mindlessness. Actual or potential applications of this research include procedures to reduce the information-processing demand imposed by vigilance tasks and the stress associated with such tasks.

Adult↗
PubMed2003

Automatic-controlled information processing and error detection in a simulated pharmacy-verification task.

The relationships between attentional variables and information-processing demands of pharmacy dispensing tasks that contribute to difficulties in cognitive performance are not well-known. In the present study, a psychological approach to medical dispensing errors, the cognitive-systems performance model of Grasha, was employed to evaluate the contributions of individual differences in attention and alterations in visual task information on simulated pharmacy-verification performance, perceived workload, and self-reported stress. 73 college-age volunteers completed a pretest battery containing psychological measures of automatic and controlled information processing, and one-week later spent 265 min. completing the end visual-inspection process for 200 simulated prescriptions, 27% of which contained artificially inserted errors. Evidence suggesting that both automatic and controlled processes underlie performance of a simulated pharmacy-verification task was obtained. Individual differences in controlled information processing were mildly predictive of detection accuracy, while contrary to expectations, automatic processing scores did not produce significant relationships. Detection associated with experimental alterations in font size (12-pt. vs 6-pt.) of critical prescription label information was partially in line with expectations from the cognitive-systems performance model, while additional visual enhancements via a magnification/illumination device yielded mixed results. Finally, reports of perceived workload (NASA Task Load Index) and specific patterns of self-reported stress (Dundee Stress State Questionnaire) were consistent with a three-tier behavioral framework offered recently by Matthews, Davies, Westerman, and Stammers for predicting behaviors along the automatic-controlled continuum.

Adult↗
PubMed2002

Fundamental dimensions of subjective state in performance settings: task engagement, distress, and worry.

Subjective state constructs are defined within the traditional domains of affect, motivation, and cognition. Currently, there is no overarching state model that interrelates constructs within the different domains. This article reports 3 studies that provide converging evidence for 3 fundamental state dimensions labeled task engagement, distress, and worry that integrate constructs across the traditional domains. Study 1 differentiated the state dimensions by factor analysis of the scales of the Dundee Stress State Questionnaire (G. Matthews et al., 1999). Study 2 showed differential state response to performance of tasks making different cognitive demands. Study 3 showed that states are correlated with differing patterns of appraisal and coping. The 3 stress state dimensions provide a general descriptive framework consistent with transactional accounts of stress and performance.

Adaptation, Psychological↗
PubMed2002

Task-induced fatigue states and simulated driving performance.

States of fatigue are implicated in driver impairment and motor vehicle accidents. This article reports two studies investigating two possible mechanisms for performance impairment: (1) loss of attentional resources; and (2) active regulation of matching effort to task demands. The first hypothesis predicts that fatigue effects will be accentuated by high task demands, but the second hypothesis predicts that fatigue effects will be strongest in "underload" conditions. In two studies, drivers performed a stimulated driving task, in which task demands were manipulated by varying road curvature. In a "fatigue induction" condition, the early part of the drive was occupied by performance of a demanding secondary task concurrently with driving, after which the concurrent task ceased. Post-induction driving performance was compared with a control condition in which drivers were not exposed to the induction. In both studies, the fatigue induction elicited various subjective fatigue and stress symptoms, and also raised reported workload. Fatigue effects on vehicle control and signal detection were assessed during and after the fatigue induction. The fatigue induction increased heading error, reduced steering activity, and, in the second study, reduced perceptual sensitivity on a secondary detection task. These effects were confined to driving on straight rather than on curved road sections, consistent with the effort regulation hypothesis. The second study showed that fatigue effects were moderated by a motivational manipulation. Results are interpreted within a control model, such that task-induced fatigue may reduce awareness of performance impairment, rather than reluctance or inability to mobilize compensatory effort following detection of impairment.

Adolescent↗