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PubMed1988

Effects of protriptyline on vigilance and information processing in narcolepsy.

Vigilance, memory function, and response latency on the Sternberg short-term memory scanning task were examined in eight narcoleptic patients on and off medication. Off medication, half of the patients demonstrated reduced vigilance and all displayed diminished automatic memory encoding and longer response latencies on the Sternberg memory scanning procedure relative to the treated condition. Protriptyline normalized vigilance in half of the patients, while response latency and automatic information processing significantly improved in all. These findings are discussed with regard to the potential effect of the medication on central nervous system arousal.

Adult↗
PubMed1979

[The influence of vigilance on DC response in human visual evoked potential (author's transl)].

Visual evoked cortical potentials elicited by long-lasting stimuli of red light were examined in eight subjects under different conditions of vigilance. The DC components of the evoked potentials were compared with the delta and theta activity (0-7.5 Hz) of the EEG by means of frequency power spectra. The results are: 1) A proportional relationship exists between the amplitude of the negative DC component of the evoked potential and the theta and delta activity in the EEG. 2) Under conditions of low vigilance the negative DC potential does not return immediately to the baseline after the off-effect. Instead it may reach a second peak. 3) Under conditions of high vigilance, the DC potential may reverse its polarity. Its return to the baseline following the off-effect is immediate. 4) No dependence of the cortical DC potential on the intensity of the light stimulus could be demonstrated. 5) Since the negative potential outlasts the visual stimulus and could be recorded at the occiput and the vertex, it may be regarded as a nonspecific arousal reaction. Furthermore, since the positive DC potential can only be recorded at the occiput, it is regarded as a specific stimulus-correlated response.

Adult↗
PubMed1980

Smoking and vigilance. The effects of tobacco smoking on CFF as related to personality and smoking habits.

The effects of tobacco smoking on vigilance (Critical Flicker Fusion, CFF) measured by a computerized forced-choice interactive technique, was studied in a group of 28 male moderate smokers. Subjects participated in a Smoking (S) and a Non-Smoking (NS) condition each of 1 h duration. CFF performance was measured during fifteen 2-min trials in each condition. In the S condition subjects smoked three puffs during each of five pauses between five successive trials. Vigilance was significantly improved by smoking. An initial sharp increase in CFF performance was noticed with a maximum 8 min after the first puff. Performance was significantly higher in the S condition compared to the NS condition up to 20 min after the last puff. Two extreme groups, based on differences in CFF performance between the S and NS condition were compared by questionnaires on personality and smoking habits. The most improved group had significantly higher scores in an extraversion scale. Ratings of the effect of smoking on level of alertness indicated that the objective effect of increased vigilance had no counterpart on the subjective level.

Adult↗
PubMed1982

[Investigation of the influence of vigilance on the nystagmic reaction (author's transl)].

A modification of mental arithmetic (MMA) combined with a key press technique was used to raise the patient's level of vigilance during routine investigation of vestibular function. The effect of MMA is studied by comparing succeeding pendular tests under different conditions. Group I: 81 patients had the first pendular test without and the second with MMA. Control group II: 31 patients had the tests in opposite order. The nystagmograms were analysed by computer. The application of the MMA-method resulted in a significantly increased average reaction intensity with differences up to 20% and more, according to the considered nystagmus parameter. This effect does not depend on the chronological order of the tests with or without MMA. On the other hand, in both groups a higher level of vigilance is correlated with less nystagmic beats (5-8%). Therefore, the number of beats does not show the characteristics of typical intensity parameters. The comparison of the absolute values of the analysed parameters shows good reproducibility of the average results under identical circumstances. In the last 4 years the MMA-method turned out to be easily applicable. For all these reasons, this method was included into the routine examination of vestibular system function to raise and keep constant the level of vigilance.

Adolescent↗
PubMed1976

Alterations in the vigilance performance of children receiving amitriptyline and methylphenidate pharmacotherapy.

The effects of amitriptyline (Elavil) and methylphenidate (Ritalin) on the vigilance of 20 hyperactive/aggressive children was investigated using an auditory version of the Continuous Performance Test (CPT). Over the course of this letter-detection task, correct detections tended to return to pretreatment levels under placebo, but were maintained at significantly improved levels under amitriptyline and methylphenidate. The relatively steep performance decrement which occurred in the placebo condition was found to be associated with a progressive increase in responses to the letter which immediately followed a target letter. Treating these 'late' responses as slow but 'correct' detections failed to eliminate the treatment effects obtained with amitriptyline and methylphenidate. It was concluded that in addition to keeping detection response latencies from increasing, the medications produced a heightened level of vigilance which resulted in an absolute increase in the number of correct detections. The facilitation of vigilance performance by amitriptyline was in apparent contradiction to reports by parents and teachers that children appeared 'drowsy' while receiving this medication. Findings of the study suggested that children's ability to process information was unaffected by the reported side effect.

Amitriptyline↗
PubMed1990

Steady-state visually evoked potential topography associated with a visual vigilance task.

This paper describes data which demonstrate a correlation between the magnitude of the Steady-State Visually Evoked Potential (SSVEP) and visual vigilance. The SSVEP was recorded from 64 scalp sites and elicited by a 13Hz uniform visual flicker presented continuously while subjects undertook a visual vigilance task. Fifteen right-handed males were required to view three times a series of 180 geometrical shapes comprising a sequence of 60 squares, 60 circles and a further 60 squares. Each viewing of the 180 shapes constituted a trial. Trials 1 and 2 were identical while trial 3 differed from the first two in that one of the circles was modified. Subjects were ignorant as to the location of the modified circle and prior to the third trial, were challenged to identify the modified circle. A comparison of trials 2 and 3 indicated that the appearance of the modified circle was associated with an attenuation of the SSVEP in the occipito/parietal region. The same comparison indicated a pronounced SSVEP attenuation in the centro/parietal region during the interval that subjects were anticipating the appearance of the modified circle. These results suggest a distinction between the cortical activation patterns occurring during different phases of a visual vigilance task.

Adolescent↗
PubMed1995

Use of computerized visual performance test in assessing day-time vigilance in patients with sleep apneas and restless sleep.

We have studied day-time vigilance in 31 patients (median age 49 years) with suspected sleep disorders using a new visual reaction time and performance test. The findings in the day-time vigilance test were compared with the number of desaturation events and movement arousals measured with a sensitive movement detector in the night-time. In our statistical model the high number of desaturations correlated with a high dispersion in reaction-times. The squared multiple r was 0.465 in a model where the dispersion of reaction times was the dependent variable and the number of desaturations, duration of quiet sleep and the mode of oxygen saturation were independent variables. A high amount of body movements (movement arousals, duration less than 5 seconds) correlated with gradual deterioration in the performance test. The squared multiple r was 0.447 in a model where the regression coefficient of reaction times was the dependent variable and active sleep and number of body movements less than 5 seconds in duration were the independent variables. Frequent arousals in apnoeic patients are observed in hyper-excitable responders and are known to cause sleep deprivation and hypersomnia. Our findings in desaturating patients indicate that in those with a low chemoreceptor response to hypoxia the failure in day-time regulation of vigilance may differ from the failure associated with sleep-deprivation.

Arousal↗
PubMed1995

The relationship between intelligence and vigilance in children at risk.

The purpose of this study was to compare two competing models as an explanation of the relationship between intelligence and sustained attention in educationally at-risk kindergarten children. One model assumes that lower-IQ subjects allocate greater amounts of attentional resource of information-processing tasks than higher-IQ subjects, whereas the other model assumes that a "less-than" optimal level of arousal is associated with decrements in task performance across time. Twenty-nine teacher-nominated at-risk and 29 normal achieving kindergarten students were administered the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R) and vigilance taks. Signal detection measures of stimulus detectability (d'), decision criterion (beta), correct detections, and false alarms were used to assess children's sustained attention across three time periods (2, 4, and 6 min). The important results were (a) high-risk children were inferior on d' measures when compared to normal achieving children, (b) vigilance measures did not vary over time in either group, and (c) intelligence and vigilance shared a common factor in high-risk, but not low-risk, children. The results suggest that children educationally at risk suffer deficits related to attentional capacity for processing information.

Achievement↗
PubMed1995

Vigilance impairment after a single dose of benzodiazepines.

While outpatients or other users of therapeutic drugs have to be informed about the risk of impaired functioning during driving or work, the prescribing physician needs to be familiar with the side effects of alternative drugs in order to select the most suitable treatment. With this aim, several types of benzodiazepine anxiolytics in low anxiolytic doses (diazepam 5 mg or 10 mg, nitrazepam 5 mg, oxazepam 10 mg, medazepam 10 mg, and alprazolam 0.2 or 0.5 mg-per 2m2 body surface) were tested under laboratory conditions for their effects on vigilance performance. In a double-blind design, 145 healthy volunteers performed a 60 min vigilance test (composed of discriminatory reactions to acoustic stimuli and a secondary visual tracking task) and four short psychomotor tests (lasting 1-7 min each) before and after a single dose of drug or placebo. Subjects described their perception of the drug effect with the help of a mood check list, and fatigue, sleepiness, and effort scales. Only diazepam 5 mg and 10 mg, alprazolam 0.5 mg, and nitrazepam 5 mg caused significant deterioration in vigilance performance along with perceived sleepiness and the need for a greater effort to overcome it. The onset of diazepam effect was quicker, whereas alprazolam effect lasted longer. No effect was noted in the short psychomotor tests except for the Bourdon Cancellation Test, where the first phase of diazepam effect was registered.

Acoustic Stimulation↗
PubMed1993

Stimulant drugs and vigilance performance: a review.

The literature on the effects of some stimulant drugs (amphetamine, methylphenidate, caffeine, and nicotine) on vigilance performance is reviewed. Improvement of overall level of performance (both accuracy and speed) after the intake of amphetamine, caffeine, and nicotine has often been reported, and the decrement in performance with time has been shown to be prevented especially with amphetamine and nicotine. Effects on false alarms are negligible. In studies where a test battery was employed, vigilance tasks appeared to be the most sensitive performance tests in detecting the effects of stimulants; however, different vigilance tasks may measure different aspects of mental functions. There is no support for earlier conclusions that improvements are noticed only in fatigued subjects in protracted sessions. Evidence from several studies does not support the hypothesis that improvements are only a recovery of withdrawal-induced impairment. Because positive effects have been obtained with drugs possessing different mechanisms of action, there is as yet no clear support for a noradrenergic, dopaminergic, or cholinergic theory of sustained attention. Simple neurotransmitter theories of attention and information processing may be untenable.

Animals↗
PubMed1997

Vigilance and EEG power in rats: effects of potent inhibitors of the neuronal nitric oxide synthase.

We examined the effects of potent neuronal nitric oxide synthase inhibitors, 3-bromo-7-nitro indazole (3-Br-7-NI) and S-methyl-L-thiocitrulline (S-Me-TC) on general behaviour, vigilance stages and electroencephalographic (EEG) power spectra in rats. In addition, we studied the effect of 7-nitro indazole (7-NI) on EEG power spectra in rats during dark and light periods. 3-Br-7-NI induced ptosis and decrease of slow wave sleep and rapid eye movement sleep in the rat. 7-NI and 3-Br-7-NI reduced the EEG power density in all frequency bands in the rat, suggesting a depression of central neuronal activity. This effect of 7-NI was more prominent during the day than during the night, indicating a circadian variation in the nitric oxide synthase (NOS) response to NOS inhibitor. EEG power was the most reduced in the 7-9 Hz range of the rhythmic slow activity (theta rhythm), which is in accordance with decreased locomotion observed following administration of NOS inhibitors. Although S-Me-TC is the most potent NOS inhibitor in vitro experiments, it had less effect on vigilance and EEG power in the rat than other NOS inhibitors used in this study, probably due to its short lasting and blood pressure raising effect. The present results indicate that nitric oxide exerts an excitatory and circadian dependent effect in the central neuronal structures involved in the regulation of vigilance.

Animals↗
PubMed2000

Serotonergic mechanisms involved in the attentional and vigilance task performance of rats and the palliative action of aniracetam.

Central serotonergic systems play an important role in regulating mood/emotion, cognition, sleep and wakefulness, appetite and locomotion and body temperature via multiple receptor subtypes. Among them, 5-HT1A and 5-HT2A/2C receptors have opposite effects with respect to certain functions. The aim of the present study was to compare the effects of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a selective 5-HT1A receptor agonist, and 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), a selective 5-HT2A/2C receptor agonist, on the performance of middle-aged rats in a two-lever choice reaction task that assessed attention and vigilance functions. We also examined the effects of aniracetam, a cognition enhancer, and its major metabolites on the induced performance impairments. 8-OH-DPAT (0.3 mg/kg s.c.) reduced response speed and choice accuracy and increased response omission with a reduction of task-associated motor activity without inducing motor inability or motivational changes. These findings indicate a specific disturbance of attentional and vigilance processes. DOI caused similar impairments at the highest dose tested (3 mg/kg s.c.); at a lower dose (1 mg/kg s.c.), however, it selectively attenuated the response speed, suggesting a selective attention deficit. (-)-Alprenolol, a non-selective 5-HT1A receptor antagonist, and ritanserin, a preferential 5-HT2A receptor antagonist, blocked the 8-OH-DPAT- and DOI-induced performance impairments respectively. Aniracetam ameliorated all the performance deficits, and the metabolites N-anisoyl-GABA and 2-pyrrolidinone partially mimicked the aniracetam effect in the 8-OHDPAT-induced attentional and vigilance impairments. Nefiracetam, another cognition enhancer, improved only the 8-OH-DPAT-induced impairments. Each compound tested alone had no effect on task performance. These results indicate that both serotonergic regulations, possibly via presynaptic 5-HT1A receptors and more likely via postsynaptic 5-HT2A receptors, lead similarly to attention deficits.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2002

Assessing a vigilance decrement in aged rats: effects of pre-feeding, task manipulation, and psychostimulants.

RATIONALE: In studies assessing sustained attention in humans, performance is often characterised by a decline in function over time. This response pattern, termed the vigilance decrement, is sensitive to manipulations affecting task difficulty, and to reversal with psychostimulant drugs. A valid test of attention in non-human species requires both comparable characteristics of performance, and sensitivity to similar psychoactive drugs. The five-choice serial reaction time task (5-CSRTT) has been described as a test of sustained attention in the rat, however, studies describing vigilance decrements and performance effects of psychostimulants in this task are scarce. OBJECTIVES: We manipulated the standard 5-CSRTT to determine under which conditions a replicable vigilance decrement could be observed, and sought to determine whether this pattern of changes was sensitive to psychostimulant administration. METHODS: One and two-year-old rats performed in five-choice sessions extended to 250 trials. Task difficulty was manipulated by either increasing or decreasing the duration of stimulus presentation, and pre-feeding studies were performed to control for effects of the additional food earned. In the two-year-old group dose-responses were then derived for nicotine (0.1-0.4 mg/kg), amphetamine (0.05-0.4 mg/kg) and caffeine (3-10 mg/kg). RESULTS: Extending five-choice sessions revealed a decline in the performance of two-year-old rats as a function of trial number. Increasing task difficulty induced a response-decrement in one-year old rats; whilst reducing it enhanced the performance of two-year-old rats to that observed in younger subjects. Pre-feeding did not alter the response patterns observed in either group. Nicotine, amphetamine, and caffeine all reversed the performance decrement observed. CONCLUSIONS: These results demonstrate that similar performance characteristics can be observed in both human and rat, serving to validate further the 5-CSRTT as a measure of sustained attention.

Aging↗
PubMed2005

Hyperactivity, impaired learning on a vigilance task, and a differential response to methylphenidate in the TRbetaPV knock-in mouse.

RATIONALE: The thyroid hormones (T3 and T4) play a critical role in brain development, and thyroid abnormalities have been linked to a variety of psychiatric and neuropsychological disorders. Among patients with the rare genetic syndrome resistance to thyroid hormone (RTH), 40-70% meet the diagnostic criteria for attention deficit-hyperactivity disorder (ADHD). RTH is caused by a mutation in the thyroid receptor beta (Thrb) gene that results in reduced binding of T3 to its receptor and elevated concentrations of T3, T4, and thyroid-stimulating hormone. OBJECTIVES: We tested a knock-in (KI) mouse expressing a mutant TRbeta allele (TRbetaPV) for the behavioral features of ADHD and their response to methylphenidate (MPH). METHODS: The locomotor activity of the TRbetaPV KI mice was measured in activity monitors over multiple sessions. Sustained attention and the effects of MPH on attention were assessed using a vigilance task. RESULTS: The TRbetaPV KI mice are hyperactive and have learning deficits on a vigilance task. Doses of MPH that impair the vigilance performance of wild-type mice do not affect the performance of the TRbetaPV KI mice. CONCLUSIONS: The TRbetaPV KI mice provide a tool for studying the underlying neural deficits that contribute to thyroid-related neurological disorders, hyperactivity, and altered responsiveness to MPH.

Alleles↗
PubMed1999

Effects of nicotine administered via a transdermal delivery system on vigilance: a repeated measure study.

Fifteen 18- to 25-year-old male smokers were tested in a within-subjects design to determine the influence of a transdermal patch of 21 mg nicotine on vigilance. Subjects were tested on the RVIP test (Rapid Visual Information Processing test) 1.30, 3.00 and 6.30 h after patch application, to verify the involvement of the dose of nicotine on the performance. This study confirms and extends the increasing effects of nicotine on vigilance previously found with orally and transdermally given nicotine. Moreover, it showed that such performance was independent of the time of nicotine absorption (1.30, 3.00 and 6.30 h after patch application), which suggests that a relatively low dose of nicotine suffices to activate vigilance processing. Regarding motor performance, no convincing effect of nicotine was observed on reaction time.

Administration, Cutaneous↗
PubMed1989

Rilmenidine and vigilance. Review of clinical studies.

In this study, the possible effects of rilmenidine on vigilance are evaluated. Sedation is the most disturbing side effect of alpha 2-agonists, especially during the first weeks of treatment. The level of vigilance was first determined by assessing drowsiness using visual analogue scales and/or by several psychometric tests in four pharmacoclinical studies in healthy subjects or in hypertensive patients: three studies with single administration of rilmenidine (0.5 to 3.0 mg) and one study with repeated administration for three days. These studies were double-blind, Latin-square designed, and controlled versus placebo (in all studies) and versus clonidine (in three studies). Analysis of these results illustrated that after short-term and repeated administration: (1) the effects on vigilance observed with rilmenidine 1 mg did not differ statistically from data observed with placebo; and (2) sedative effects observed with clonidine were significantly greater than with rilmenidine, at equihypotensive doses. Daytime drowsiness was systematically assessed and graded by inciting questioning at each visit in five clinical studies. Ambulatory hypertensive patients were treated with rilmenidine (1 mg per day or 1 mg twice a day). These studies were controlled versus placebo (one study for two weeks, 120 patients; and one study for one month, 126 patients), hydrochlorothiazide (six weeks, 56 patients), clonidine (six weeks, 333 patients), and methyldopa (three months, 157 patients). The results showed that: (1) drowsiness observed with rilmenidine did not differ statistically from that observed with placebo or diuretic; and (2) drowsiness occurred less frequently with rilmenidine than with reference alpha 2-agonists at equihypotensive doses. In conclusion, these results confirm in current clinical use the dissociation already observed in laboratory animals between the antihypertensive effects and the sedative effects and may distinguish rilmenidine among alpha 2-agonists.

Adrenergic alpha-Agonists↗
PubMed1985

[Value of the sleep diary in the study of vigilance dis].

This study presents an easy and practical subjective method for evaluating vigilance disorders: the sleep diary. We used it in hypersomnia and deficits of waking. Sleep diaries were filled in by 10 control and 22 hypersomniac subjects. Twenty-four hour polyhypnographic recording allowed the classification of hypersomnia as 13 narcolepsies, 9 hypersomnias with a prevalence of PS, 2 'harmonious' hypersomnias and 1 waking deficit. The sleep diary data (amount of nocturnal sleep and diurnal sleep onset and vigilance decrease) were compared with polygraphic results. According to the diary data, 3 groups of hypersomnia appeared with regard to the time at which sleep onset occurred. The first group presented an increase of sleep onsets at 2 p.m. In the second group, almost exclusively composed of narcoleptic subjects, sleep onsets occurred every 2 h and in the third group they were distributed throughout the day. These results suggest different physiological mechanisms for these 3 groups of hypersomnia. Finally, the sleep diary seems to be an easy and cheap method of evaluating vigilance disorders in hypersomniac subjects during their everyday life.

Adult↗
PubMed1994

Vigilance and effects of fatigability, practice and motivation on simple reaction time tests in patients with lesion of the frontal lobe.

Despite the wide use of RT tests in brain-damaged patients assessment, effects of the level of vigilance, fatigability, practice and motivation on RT have been poorly investigated. We assessed vigilance and effects of fatigability, practice and motivation on brain-damaged patients suffering from lesion of the prefrontal cortex prominent in basofrontal areas and controls using simple RT tests. Our study showed fatigability and practice effects which did not affect RT differences between groups, whereas motivation effect was not significant. Finally, patients did not suffer from a deficit of vigilance. These results suggest that the attentional disorders demonstrated in the same patient group were related neither to a higher sensitivity to fatigability nor to an insufficient practice.

Adolescent↗