Showing papers on "Vigilance (psychology) published in 1981"

Control and Automatic Processing During Tasks Requiring Sustained Attention: A New Approach to Vigilance:

Abstract: Vigilance decrements are interpreted within a two-process (automatic/control) theory of human information processing, and the theoretical components of the normal vigilance curve are discussed in relation to type of processing and amount of practice. Two experiments were conducted showing significant vigilance decrements when subjects utilized effortful control processing; the normal decrement was not observed when effortless automatic processing was possible. Maximum vigilance decrements occur when subjects must continually and redundantly allocate control-processing resources. Results disconfirm the habituation hypothesis. It is concluded that structuring a task such that there is a consistent relationship between signals and noise will reduce vigilance problems. System design implications suggest that tasks should be structured to minimize continuous and repetitive control processing. Methods for developing vigilance-decrement-resistant automatic processing are discussed.

Factors affecting an anaesthetist's work: some findings on vigilance and performance.

Abstract: This paper reviews factors which may influence the vigilance tasks of an anaesthetist during an anaesthetic. Vigilance tasks are found to be unlike any other automatic, repetitive or monotonous tasks. While many factors affect vigilance and may result in performance decrements during psychological testing, little of this work has been done on anaesthetists. We suggest, however, that there are many parallels between findings related to vigilance in general and the type of work done by anaesthetists. Implications of major factors are discussed, and recommendations for further study are proposed. Language: en

Diurnal variation in vigilance efficiency.

Abstract: Five sets of data are presented, obtained from studies that examined the influence of time of day on auditory vigilance performance during the normal waking day. Although both hits and false alarms...

Effects of the rate and regularity of background events on sustained attention

Abstract: Subjects listened for occasional increments in the intensity of recurrent acoustic pulses. Detection probability varied inversely with the rate of repetition of neutral background events in which critical signals were arrayed (the background event rate). Contrary to expectations derived from a habituation model of vigilance (Mackworth, 1968, 1970), the presentation of neutral events in a temporally irregular manner suppressed rather than enhanced the detection of critical signals and failed to attenuate performance differences associated with variations in background event rate.

Vigilance in hyperactive and normal children on a self-paced operant task.

Abstract: SUMMARY A self-paced vigilance task adapted from operant work was employed to study visual attention in hyperactive and normal children. The task distinguishes between two components of vigilance, observing responses and signal detention responses which are further divided into hits and false alarms. All subjects is were exposed to the same number of signal presentations under a low (VI 53) density and a high (VI 15) density schedule. Hyperactive children emitted a lower percentage of hits and a greater percentage of false alarms than normals. Hyperactive children showed observing response rater than normals. The educational implications of these findings are considered.

Beta-receptor blocking therapy in hypertensive patients--effects on vigilance and behaviour.

Abstract: In 13 hypertensive patients taking the beta-receptor blocker atenolol, EEG and behaviour effects were studied. Using a single-blind sequential trial design, a 5-d placebo period was followed by a 6-d atenolol treatment period (100 mg/d). During either treatment period, two examinations yielded data derived from neurophysiological, test-psychological, and cardiovascular measurements. The statistically significant changes due to atenolol therapy indicated an improvement of vigilance, a smooth anxiolytic and tranquilizing effect, and at least no negative influences on discriminatory reaction time and concentration ability. The primary therapeutic effects were significant falls in systolic and diastolic blood pressure as well as in pulse rates. The study is still in progress and will be completed after 20 patients are reached. The data will then be reanalyzed in order to get further insight into CNS effects of a beta-blocking therapy concerning favorable vs. poor drug responders. Language: en

Influence of the beta-blocking atenolol and other medications on visual reaction time.

Abstract: Visual reaction time as a measure of vigilance and of the psychophysiological condition of subjects, was determined after combined physical and mental stress to examine the influence of beta blockade. Using the technique of electro-oculography, 40 subjects aged 25.7 +/- 6 years, with a mean blood pressure of 126/79 torr, were studied in a double-blind crossover design after application of placebo or 50 mg atenolol for 3 d. Visual reaction time was defined as the time between display of a peripheral light signal and the start of the eye movement that shifts the direction of gaze from the reference point to the stimulus. The results of the study show that, under these experimental conditions, there is a positive effect of beta blocker medication on vigilance. FINDINGS of other authors are discussed. To prove the sensitivity of the test method in a preliminary study, the effects of the well-known drugs fenethylline-hydrochioride, diazepam, oxazepam, and alcohol on visual reaction time were investigated. Language: en

Sustained visual attention and carbon monoxide: elimination of adaptation effects.

Abstract: Eighteen subjects performed a 1-h visual vigilance task, once during a control condition, (filtered air) and once during an experimental condition (CO). The COHb level was elevated to 5% utilizing a bolus maintenance technique which raised the COHb level rapidly so that there would be no possibility of an adaptation occurring prior to vigilance testing. Physiological measurements included heart rate, blood pressure, and ventilation. Neither vigilance performance nor the physiological variables was statistically affected by the 5% COHb level. Subjects identified a significantly (p less than 0.05) higher percentage of signals with the high frequency of signal presentation as compared to the low frequency under both filtered air and the 5% COHb level. Signal detection improved in 12 subjects during minutes 0-15, while 10 subjects showed improvement during minutes 31-45 with an elevated COHb level. The subjective questionnaire indicated that CO significantly (p less than 0.01) decreased the subjects' confidence concerning their performance on the vigilance task, as well as causing significant (p less than 0.05) irritation of the eyes and throat.

Cognitive Differentiation and the Perception of Older Persons: A Test of the Vigilance Hypothesis

Abstract: Using data collected from a probability sample of 1012 adults, this study examines the relationships among knowledge about aging, net negative bias in knowledge about aging, fear about the consequences of being old, and differentiation of image of older persons. The findings that negative bias in knowledge about aging and fear of the consequences of being old predict differentiated images of older people provides support for the vigilance hypothesis as applied to the stimulus-object "older person."

Electrodermal responses to auditory stimuli with different significance in neurological patients.

Abstract: In 16 neurological patients with different levels of severely disturbed vigilance and 16 healthy subjects electrodermal responses to the name and the name backwards were elicited. In the most severely impaired patients, no differences were found between stimulus conditions. In less severe cases, significantly larger responses to the name were found but only on initial trials. In normal subjects differences persisted throughout 10 presentations of each stimulus. All subject groups demonstrated habituation.

Reinforcement, skin conductance, and performance in a vigilance-reaction time task

Abstract: Three experiments were conducted using normal adults to assess the effects of contingencies of reinforcement on vigilance-reaction time performance and skin conductance. There was significant, direct relationship between rate of skin conductance responding and speed of performance. Performance was faster and skin conductance responses were more frequent when response-contingent monetary reinforcement was available than when either feedback alone or no feedback was provided. The data suggest that central facilitating mechanisms are activated by complex interactions among several factors, including the likely consequences of task performance.

Vigilance and beta blockade. The influence of the beta blocker atenolol and other substances on the reaction time of the visual system

Abstract: Visual reaction times as a measure of vigilance and of the psycho-physiological condition of subjects was determined after combined physical and mental stress to examine beta-blocker influence. Using the technique of electrooculography 40 subjects aged 25,7 +/- 6 with a mean blood pressure to 126/79 mmHg were measured in a double-blind cross-over design after application of placebo or 50 mg of atenolol (Tenormin) for 3 days. Visual reaction time was defined as the time between display of a peripheral light signal and the start of the eye movement that shifts the direction of gaze from the reference point to the stimulus. The results of the study show, that under these experimental conditions there is a positive effect of beta-blocker medication on vigilance. Findings of other authors are discussed. To prove the sensitivity of the test method in a preliminary study, the effects of the well-described drugs fenetyllinhydrochloride, diazepam, oxazepam and alcohol on visual reaction time were investigated.

Remediation Efforts for Hyperactivity: Training in Attention or Inhibitory Control.

Abstract: To compare various cognitive treatment approaches for ameliorating difficulties of hyperactive children on tasks requiring sustained vigilance and accuracy, 48 hyperactive boys (mean age 9 years 4 months) were randomly assigned to one of.four training conditions: dnhibitory control training, attention training, combined training, or control. The combination of attentional and inhibitory control strategies was most effective in enhancing Ss' cognitive performance. Results were interpreted to support the hypOthesip that impulse and attention control problems occur concurrently in hyperactive Ss, although remediation in attentional deploying strategies is necessary for enhancing their cognitive performance. Findings furtber suggest that training solely in inhibitory control is not sufficient for enhancing cognitiye performance among hyperactive,children. (Author)

The effects of continuous exposure to carbon monoxide on auditory vigilance in man.

Abstract: Six different groups of non-smoking young male subjects were studied separately for 18 consecutive days each in a closed controlled-environmental human exposure chamber. Each group was subjected to a 5-day control period in fresh air followed successively by an 8-day period of continuous exposure to 50 ppm, 15 ppm or 0 ppm (control) by volume of carbon monoxide (CO) in air, and a 5-day recovery period in fresh air. The subjects performed a 1-h auditory vigilance task every day at the same time of day in a fixed qualitative, quantitative, and temporal relationship with food intake, consumption of stimulating beverages, physical activity, and sleep. It was concluded that such CO exposure, involving the continuous carriage of carboxyhaemoglobin loads up to 7%, was without significant effect on auditory vigilance.

Interaction between emotional arousal and thermoregulation in the rabbit

Abstract: Publisher Summary This chapter focuses on the interaction between emotional arousal and thermoregulation in a rabbit. The chapter presents a study that examines how changes in the level of vigilance or emotional arousal affect thermoregulation. The thermoregulatory performances were compared during quiet wakefulness and during the state of increased vigilance and emotional arousal induced by a classical aversive conditioning procedure. The experiments were carried out on three male New Zealand white rabbits, weighing between 2,500 and 3,000 g. Under urethane anesthesia, the animals were chronically implanted with electrodes for EEG, EMG, and EKG recording and a thermistor-measuring hypothalamic temperature. The thermistors were also used to record respiratory frequency and ear skin temperature. After complete recovery from surgery, the experimental sessions were carried out in a thermoregulated, sound-attenuated box whose temperature was kept constant during each experimental session but varied in different sessions on different days from 0 to 30°C. It was found that at the conditioned stimulus induces desynchronization of the EEG and a stereotyped change in all the autonomic variables studied: ear skin temperature decreases as a result of vasoconstriction, whereas the respiratory frequency and hypothalamic temperature increase.

Evaluation of disturbances of consciousness.

Abstract: Consciousness as the highest form of neuronal activity is very difficult to define. It is superior to unconditioned reflex activity and vigilance, and its most important sign is verbal signalization. Therefore, a scheme of evaluation of impaired consciousness was elaborated by the author, in which in the first group a strong painful impulse is the stimulus, in the second group of consciousness proper the word is the stimulus. This simple scheme of 8 points can be applied also by nurses.