Auditory Vigilance Task Research Articles

A comparison of the CNS effects of enprofylline and theophylline in healthy subjects assessed by performance testing and subjective measures.

1. The effects of intravenous infusions of enprofylline, theophylline, and placebo on subjective ratings and on psychological test performance were studied in a double-blind crossover experiment in 12 healthy subjects who abstained from caffeine throughout the experimental procedures. 2. Mean plasma concentrations of enprofylline were: mean 2.9 mg l-1 (range 1.9-3.4). Those for theophylline were: mean 12.1 mg l-1 (range 9.0-14.4). 3. Performance on the auditory vigilance task showed a significant improvement with theophylline compared with both enprofylline and placebo. The correct detection rates (out of 90) were 50.3, 43.4 and 39.1 respectively. A similar effect was seen with finger tapping rates: 404, 394 and 390 taps min-1 respectively. Other measures showed no significant effects, although choice reaction time showed a trend towards faster responses with theophylline. 4. Subjective ratings showed that subjects were significantly more alert with theophylline than with enprofylline. Subjects reported themselves as significantly more dizzy and ill with both active drugs compared with placebo. 5. These results suggest that emprofylline largely lacks the CNS stimulant effects of theophylline, but that the incidence of other unwanted effects of the drugs may be similar.

Self-regulation of stimulation for ADD-H children during reading and vigilance task performance.

The present study examines the hypothesis that motor responses added into rote tasks would modulate the sensation-seeking activity and impulsive errors of hyperactive (ADD-H) children. To this purpose 22 ADD-H and 25 comparison children were administered two repetitive tasks (word decoding and an auditory vigilance task) under both an active response and a passive response condition. Findings were that the impulsive errors, talking/noisemaking, and activity of ADD-H children was normalized (i.e., did not differ from comparison children) only in the high stimulation active response conditions. Behavioral improvements for ADD-H children were documented in both tasks in the active condition, but performance gains were found only in the vigilance task. The findings supported predictions derived from the optimal stimulation theory that the excessive activity and attraction to novel stimuli of ADD-H children can be channeled into appropriate instrumental motor and attention responses.

Effects of prolonged sleep deprivation, with and without chronic physical exercise, on mood and performance.

ABSTRACTThe effects of physical exercise and sleep deprivation on mood and cognitive performance were studied in 12 healthy young male volunteers deprived of sleep on two occasions. During the first 60‐hr period without sleep, half of the subjects walked on a treadmill at 25–30% of their maximum aerobic capacity (Exercise condition) for 1 out of every 3 hrs while the remaining 6 subjects remained physically inactive (No Exercise condition) during that same hour. Eight weeks later the same 12 subjects underwent an identical sleep‐deprivation protocol except that those who were previously inactive exercised, while those who previously exercised remained inactive. Throughout the sleep deprivation periods, subjects in both conditions completed subjective assessments of fatigue, sleepiness and mood every 3 hrs, performed an auditory vigilance task every 6 hrs, and completed a cognitive test battery every 12 hrs. The results revealed clear decrements in mood and performance as a function of sleep loss. However, with the exception of somewhat more long reaction times in the Exercise condition, exercise neither increased nor decreased the impairment induced by sleep deprivation.

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.

Auditory vigilance during hypnosis: a brief communication.

Abstract Attention during hypnosis was measured by means of auditory vigilance tasks which Ss performed while being administered the Stanford Hypnotic Susceptibility Scale, Form C (Weitzenhoffer & Hilgard, 1962). Hypnotic responsivity was significantly and negatively correlated with Ss' performance of the tasks, indicating that relatively responsive Ss detected fewer extraneous environmental stimuli in the form of vigilance task signals than did the less responsive Ss. Discussion ensued as to how this apparent reduction in attention to environmental stimuli came about.

EMG levels in the occipitofrontalis muscles under an experimental stress condition

In view of the importance attached to the frontalis muscles by researchers into the etiology of head pain and its treatment by biofeedback techniques, it is surprising that no data have yet been reported on the functioning of the occipitalis muscles, which have a close physiological relationship to the frontales. This study explores the response of the frontalis and occipitalis muscles under a condition of experimental stress. Migraine and tension-headache sufferers were separately compared with a headache-free control group under four conditions: baseline, while listening to instructions, while carrying out an auditory vigilance task, and for a further resting period equivalent to baseline. Results showed that tension levels in the frontalis muscles were not elevated at rest in any of the experimental groups, nor were they significantly responsive to the experimental task. The occipitales however proved to have significantly higher levels in both the tension-headache and migraine groups during the task and recovery periods. The results for the tension group reached significance because of a drop in control group values. These results may have significance in determining the best site for electrode placement in biofeedback.

The physiological (EEG) nature of drowsiness and its relation to performance deficits in narcoleptics

Ten narcoleptics off medication were compared to matched controls to determine the pattern and level of electroencephalographic (EEG) vigilance, and its relation to performance ability on the 1 h Wilkinson auditory vigilance task. The narcoleptics performed significantly more poorly and spent significantly less time in wakefulness than controls. The EEG of the patients revealed continual fluctuations between wakefulness, stage 1A (slowed and diffusing alpha) and stage 1B (theta activity). Stage 2 sleep only occurred briefly in 4 patients. Stages 3, 4 and REM sleep were never encountered. Controls were continually awake aside from very brief appearances of stage 1A in 5 subjects. Narcoleptic performance during stages 1B and 2 was characterized by lapses (response omissions). Patients also demonstrated significantly more lapses as well as false positive responses than controls during wakefulness and stage 1A. Poorer performance even during wakefulness was demonstrated to be related to inability to sustain wakefulness over time. The results clarify the temporal pattern of physiological vigilance during performance in narcoleptics and also demonstrate the insufficiency of the lapse-microsleep formulation in explaining performance deterioration in these patients.

Auditory evoked potentials compared to performance measures and EEG in assessing excessive daytime sleepiness in narcolepsy-cataplexy

The AEP to the repetitive stimuli of the Wilkinson auditory vigilance task was compared between untreated patients with narcolepsy-cataplexy and matched controls for periods during which the tones were preceded by 13 sec or more of wakefulness (defined by EEG-polygraphic criteria). During these periods it had been found previously that narcoleptics did not perform worse than did controls. The AEP, nevertheless, showed significant differences for narcoleptics. These were similar to changes described for drowsiness in normals. The AEP, therefore, showed changes related to excessive daytime drowsiness in narcolepsy-cataplexy when a sensitive performance measure and visual analysis of EEG-polygraphic recordings did not.

Effects of ambient illumination over days on human vigilance performance.

Detection rates of 36 college students were measured for three days in an auditory vigilance task under one of three conditions of ambient illumination: dark (less than .33 lx), low (86 lx), and high (170 lx) intensity levels. Within-session performance decrements were seen in all conditions. Increasing the intensity of ambient illumination improved vigilance performance, an effect which became more potent over days. These results are discussed in terms of arousal theory and habituation.

Effects of scheduled afternoon naps and bedrest on daytime alertness

A forced-rest postulate and recuperative theory of sleep function were tested. Eighteen normal, healthy young adult males were studied in a balanced design which comprised single treatment replicates of polygraphically recorded 2:40-4:00 p.m. napping and bedrest. Under both conditions subjects were required to lie quietly in bed with eyes closed. During bedrest, stage 1 sleep episodes were allowed to intervene, but for no longer than 1.5 min simultaneously. Dependent variables of waking function were initially assessed at 12:30 p.m. for 1.2 hr and then again 20 min following the conditions from 4:20 until 5:30 p.m. Measurements were obtained from: (a) short-term memory, visual four-choice reaction time, and auditory vigilance tasks; (b) 4-7 Hz EEG theta rhythm; (c) sublingual temperature; (d) the Stanford Sleepiness Scale; and (e) mood subscales (activation, euphoria, fatigue) on an adjective check list. During bedrest compared with napping, subjects averaged significantly more: (a) stage 1 (in aggregate:...

The effects of cigarette smoking on vigilance performance.

Each of 24 Ss completed an auditory vigilance task after smoking either a "low" nicotine cigarette (12 Ss) or a "middle" nicotine cigarette (12 Ss) and served as his own control in an identical session one week before or after the test session. The smoking was followed by improved vigilance in both groups as compared with the control performance. The improvement came about in different ways for the two groups. The low nicotine group recorded improved detection, the middle nicotine group reduced false positive rate. These effects are attributed to the known differential, biphasic effects of nicotine on performance.

Sensitivity of the stanford sleepiness scale to the effects of cumulative partial sleep deprivation and recovery oversleeping.

The sensitivity of the Stanford Sleepiness Scale (SSS) to short-term cumulative partial sleep deprivation (PSD) and subsequent recovery oversleeping was examined. A repeated-measures design included 7 paid healthy undergraduate volunteers, who were normal sleepers (mean sleep time 7.6 hr), and consisted of the following schedule: (a) pre-baseline; (b)sleep reduction of 40% of 1 night (mean, 4.6 hr) for 5 nights; (c) recovery oversleeping for night 1 (mean, 10.6 Hr) and night 2 (mean, 9.1 hr); (d) post-baseline. Daytime performance testing utilized a 1 hr auditory vigilance task and four short-duration (10 min) tests, two of which have been shown sensitive to total and partial sleep loss effects. Subjects completed SSS forms every min while awake and 1-9 scales of mood and energy upon awakening. Subjective measures were analyzed across conditions for mean all-day and task-related SSS values and mood and energy ratings. A correlational analysis investigated individual correspondences between ratings and performance. Results indicate that SSS is sensitive to deficits in alertness following PSD. However, it generally does not predict individual performance efficiency and therefore cannot act as a substitute for performance measures in studies involving chronic sleep loss.

Daytime performance deficits and physiological vigilance in untreated patients with narcolepsy-cataplexy compared to controls

Ten patients, 7 female, 3 male, aged 17-65 years (mean 40) with narcolepsy-cataplexy were compared off treatment to matched controls on 4 performance tests. The tests were the 1 h Wilkinson auditory vigilance task, and 3 shorter tests including the 4-choice serial reaction time, the paced auditory serial addition task (PASAT) and digit span. Tests were counterbalanced and polygraphic recordings were done during all but the 4-choice serial RT. Subjective sleepiness was assessed by the 1-7 levels of the Stanford Sleepiness Scale and effort in the tests by a similar 1-7 scale. Practice sessions were held. Narcoleptics showed poorer performance on the more monotonous tests of auditory vigilance (fewer hits) and the 4-choice serial RT (longer reaction times, more 'gaps'). There were no significant differences between groups on the other performance tests. Narcoleptics were subjectively sleepier during all tests and over-all. But there was no good correlation between perceived degree of sleepiness and performance. They also expressed greater effort to perform the PASAT. The narcoleptics showed greater amounts of drowsiness and light sleep only during the 1 h vigilance test. For the detections of those signals (shorter times) occurring after 13 sec or more of polygraphic wakefulness, narcoleptics performed as well as controls.

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

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.

Effects of ad lib extended-delayed sleep on sensorimotor performance, memory and sleepiness in the young adult

Behavioral functions were studied in 16 healthy young adult males who slept regularly for 7–8 hr following two electrographically recorded conditions of continuous sleep. The conditions consisted of a rigidly scheduled 12–8:00 a.m. control night and an ad lib session when the times for sleep were at the subjects' own inclination. Thirty minutes after awakening from each condition measurements were obtained from (1) short-term memory, (2) visual choice reaction time and (3) auditory vigilance tasks, and (4) the Stanford Sleepiness Scale. A statistically significant augmentation of total sleep occurred on the ad lib nights (mean=9.6 hr) compared with the control condition (mean=7.5 hr) which was mainly due to an average 2.7 hr delay in awakening times. Following ad lib extended-delayed sleep there was a significant decline in performance on all tasks and significant elevation of sleepiness scale ratings 90 min after awakening. This effect of ad lib sleep, like behavioral deficits characteristically arising from disturbances in the diurnal rhythm, was mainly apparent early during testing and increased little with time. The results of the present study support the assumption that phase-delays in accustomed awakening times were largely the cause for the specific performance decrements observed rather than extended sleep per se.

Effects of electrodermal lability and payoff instructions on vigilance performance.

ABSTRACTThe psychophysiologically based personality dimension of electrodermal lability has been related to vigilance performance. The present study investigated this effect basing lability on spontaneous electrodermal fluctuations and habituation of the electrodermal orienting response, and attempted to modify performance using monetary payoffs. In an auditory vigilance task, detections and sensitivity (d′) declined across blocks, and payoffs influenced detections, commission errors, d′, and response bias in the expected directions. Although there were no main effects for spontaneous lability, habituation labiles had higher log false alarm rates, lower response bias and tended to detect more signals. Using either lability criterion, labiles did not demonstrate a vigilance decrement and were more responsive than stabiles to payoff instructions. Lability based on habituation rate was therefore more clearly related to vigilance performance than lability based on spontaneous fluctuations.

Vigilance performance and the amplitude of EEG activity.

Abstract The relationships between vigilance measures and amplitudes of different EEG frequency components, obtained by frequency analysis, were examined in an auditory vigilance task. Thirteen subjects detected a faint change of intensity of 800 Hz tone during 40min with recording EEG potential from Cz and Oi. There was a four second epoch and two categories of response were allowed. Analysis of group results showed that there were no significant changes in detection of auditory signals and EEG activity as a function of time. By correlation analysis of EEG data and detection of signals during a run characteristic relationship between theta and alpha activity with detection parameters was discovered. Decrement of correct detection and sensitivity d' was in very close relation with decrease of amplitude theta and alpha activity. On the other hand, the decision aspect of detection expressed by index beta was in negative relation with the amplitude of EEG activity. Decrease in amplitude alpha and theta activity was accompanied by increase of index beta. i.e. increase of cautiousness during detection of signals. The results were partially in accord with Welford's hypothesis of relation of statistical decision theory and activation.

Body movement and inattention in learning-disabled and normal children.

Four experiments were conducted to test various aspects of an optimal level of arousal model of hyperactivity in learning-disabled children. Vigilance performance and level of body movement were measured while learning-disabled and control children performed in an auditory vigilance task. The results suggested that body movement increased throughout the vigilance task, increased rates of external stimulation result in decreased level of body movement, and learning-disabled children differed from controls in showing higher levels of body movement and poorer vigilance performance. The results were discussed in terms of changes in arousal level and compensatory stimulus-seeking behavior.

Effects of sleep deprivation on short duration performance measures compared to the Wilkinson auditory vigilance task.

The effects of one night's total sleep deprivation were examined using the Wilkinson vigilance task and four 10 min duration performance tests. A repeated measures design was used in which eight male subjects experienced one night of sleep loss, the order of sleep loss being balanced across subjects. The four short duration performance tests consisted of choice reaction time, simple reaction time, short-term memory, and a motor task, handwriting. The results confirm the effects of one night's sleep deprivation on the vigilance task and also show that performance on the two reaction time tests was significantly impaired by the loss of sleep, but not at such a high level as for the vigilance. The short-term memory test failed to show any adverse effects of sleep loss and similarly for the handwriting. The experiment shows that two portable and brief (10 min) performance tests are sensitive indices of sleep loss and should be particularly useful for assessing levels of alertness in the field.

Tobacco smoking, personality and sex factors in auditory vigilance performance

A total of 120 university students comprising equal groups of male and female non-smokers, smokers not smoking and smokers smoking; were compared for performance on a 60 min auditory vigilance task. Non-smokers consistently detected more signals throughout the test. A significant interaction showed that while non-smokers detected fewer signals as the test progressed, smokers increased their number of detections. There were no sex differences and no overall EPI differences in scores, although extraverted non-smokers gave significantly higher scores than introverted non-smokers with the converse being present for smokers. The results are discussed in relation to hippocampal functions and indicate that smoking should be taken into account in experiments involving sustained attention.