Psychomotor Tasks Research Articles

Psychomotor Slowing in Schizophrenia

Psychomotor slowing (PS) is a cluster of symptoms that was already recognized in schizophrenia by its earliest investigators. Nevertheless, few studies have been dedicated to the clarification of the nature and the role of the phenomenon in this illness. Moreover, slowed psychomotor functioning is often not clearly delineated from reduced processing speed. The current, first review of all existing literature on the subject discusses the key findings. Firstly, PS is a clinically observable feature that is most frequently established by neuropsychological measures assessing speed of fine movements such as writing or tasks that require rapid fingertip manipulations or the maintenance of maximal speed over brief periods of time in manual activities. Moreover, the slowed performance on the various psychomotor measures has been demonstrated independent of medication and has also been found to be associated with negative symptoms and, to a lesser extent, with positive and depressive symptoms. Importantly, performance on the psychomotor tasks proved related to the patients' social, clinical, and functional outcomes. Several imaging studies showed slowed performance to coincide with dopaminergic striatal activity. Finally, conventional neuroleptics do not improve the patients' PS symptoms, in contrast to the atypical agents that do seem to produce modestly improving effects.

The effects eszopiclone 3mg on next day driving ability, cognitive and psychomotor function in patients with primary insomnia

Background:We investigated the impact of eszopiclone 3mg on next day driving ability (on-the-road brake-reaction-time, BRT) and cognitive and psychomotor performance in patients with primary insomnia.Methods:Patients with DSM-IV primary insomnia completed this study. Treatment was administered 30min before bedtime, and next day driving ability was assessed by on-the-road BRT approximately 9.5 hours postdose. A cognitive test battery measured residual effects on information processing, divided attention, psychomotor tasks, and working memory. Overnight polysomnography was conducted to assess sleep architecture; subjective ratings of morning sedation and sleep quality were also obtained.Results:There were no significant differences in BRT following night time administration of eszopiclone 3mg compared with placebo (p=0.39) and there were no significant differences in objective cognitive tests of information processing, divided attention, psychomotor tasks and working memory (p values>0.15). No significant effect on subjective next day ratings of morning sedation, coordination or mood was observed (p values>0.22). There was improvement compared with placebo (p<0.0001) in subjective ease of getting to sleep and quality of sleep the morning following dosing, and no perceived impairment of behavior following awakening or early morning awakenings. Polysomnography demonstrated significant improvements in sleep onset and maintenance.Conclusion:In this study, the first to assess next day on-the-road driving in primary insomniacs following hypnotic use, eszopiclone 3mg improved both objective and subjective measures of sleep onset and maintenance without residual impairments on next day driving ability or cognitive and psychomotor performance.Support for this study provided by Sepracor Inc., Marlborough, MA.

Psychomotor and Memory Effects of Haloperidol, Olanzapine, and Paroxetine in Healthy Subjects After Short-Term Administration

Impaired psychomotor function has been shown to be associated with clinical and functional outcome in schizophrenia. However, few studies have investigated the short-term effects of antipsychotics on the cognitive and psychomotor functions of this patient group. Because many confounding factors tend to influence the test results in patient research, this study investigates the drugs' effects in healthy volunteers. The short-term effects of haloperidol (2.5 mg), olanzapine (10 mg), and paroxetine (20 mg) on psychomotor function in 15 healthy volunteers are compared with placebo and each other. In a crossover design, the subjects completed a battery of psychomotor tasks assessing psychomotor speed, sensorimotor accuracy, visuospatial monitoring, and speed of information processing. In addition, peak velocity of saccadic eye movements and subscales of the visual analog scales were analyzed as the objective and subjective measures for sedation, respectively. Finally, the verbal memory test was used to assess the drugs' effects on memory. Apart from affecting the pursuit task where visuospatial monitoring, sensorimotor speed, and sensorimotor accuracy are measured simultaneously, haloperidol has been proven to be not associated with sedative nor with impairing effects on psychomotor function or verbal memory. In contrast, olanzapine had significant sedative effects. Moreover, the subjects displayed a significant impairment on all measures of psychomotor function and verbal memory, which was not attributable to the drug's sedative effects. After administration of paroxetine, no effects were found, with the exception of a single improvement in eye movement velocity. Short-term administration of olanzapine, and not of haloperidol, impedes several aspects of psychomotor function and verbal memory in healthy volunteers.

Acute effects of nocturnal doses of MDMA on measures of impulsivity and psychomotor performance throughout the night

Previous studies on the acute effects of MDMA on psychomotor performance and impulsivity showed that MDMA acts as a stimulant. These studies assessed performance during daytime, whereas in real life, dance-attendees leaving a party use the drug during the night. The present study aimed to assess the effects of nocturnal doses of MDMA on psychomotor performance and impulsivity during the night and after a night of sleep deprivation. Fourteen healthy subjects participated in a double-blind, placebo-controlled, two-way within-subject study. The treatment was MDMA (75 and 50 mg) divided over the evening or double placebo. Psychomotor and impulsivity tasks were conducted four times throughout the evening and night. A vigilance test was conducted once, at 5 A.M.,: and a sleepiness scale was presented to the subjects ten times throughout the evening and night. MDMA impaired tracking performance in a simple tracking task. Divided attention task performance was also impaired as indicated by a decrease in secondary task performance under the influence of MDMA compared with placebo. MDMA did not affect impulsivity measures. Vigilance performance decreased as a function of time on task, but this decrement was less during MDMA treatment compared to placebo. After the administration of MDMA, the sleepiness scale scores were lower during the night when compared with placebo. This difference between MDMA and placebo disappeared in the morning. It is concluded that nocturnal doses of MDMA may produce impairments of tracking performance and divided attention throughout the night that are additive to performance impairment produced by sleep loss.

Effects of highly active antiretroviral therapy (HAART) on psychomotor performance in children with HIV disease

This study assesses the effects of HAART on psychomotor performance of symptomatic HIV-infected children. It is one of the first studies to look at neurobehavioral functioning in children infected with HIV in resource-limited countries. A longitudinal pilot study of vertically HIV-infected children at the HIV Netherlands Australia Thailand Research Collaboration Center in Bangkok, Thailand. A total of 34 children participated in the study of whom 16 had never received antiretroviral (ARV) therapy and were about to start HAART (Newly treated children), 7 did not receive antiretroviral therapy (Untreated children) and 11 had been treated with HAART for more than one year (HAART experienced children). All children were administered 4 psychomotor tasks at baseline and after 4 months. The Newly treated and the Untreated children were also evaluated after 12 months. In general, the children performed similarly on all psychomotor tasks at baseline. After 12 months of HAART, there was a significant increase in CD4% in the Newly treated group. Overall, psychomotor performance did not change at the 4-month evaluation in all groups. At the 12-month evaluation psychomotor performance had deteriorated substantially on all tasks in both the Newly treated and the Untreated children. There was no significant difference in psychomotor functioning between children newly treated, previously treated and untreated with HAART over the course of one year. Psychomotor performance deteriorated after 12 months of HAART, which provides important indications concerning the lack of benefits of HAART on psychomotor functions in children despite immunologic reconstitution. Further research with larger sample sizes is needed to confirm these findings.

Throughput: A simple performance index with desirable characteristics

Throughput is a corrected response rate measure giving the number of successes per unit of discretionary time. It is a simple but general index applicable to psychomotor, behavioral, and cognitive tasks in which response times are measured. This measure has several attractive features: (1) It allows comparisons to be made across various tasks in which speed and accuracy are meaningful and measurable, independently of temporal differences in hardware, software, and procedures; (2) under conditions in which both speed and accuracy decline (or improve), throughput will be a more sensitive index of performance than either alone will be; and (3) in those tasks in which the speed-accuracy trade-off phenomenon operates, throughput will tend to be relatively less variable than either component alone will be. The measure allows both behavioral and information-processing interpretations of data and may be useful as a simple composite index, a measure of effectiveness or of cognitive efficiency [corrected] in studies investigating performance degradation or enhancement.

Dietary tyrosine benefits cognitive and psychomotor performance during body cooling

Supplemental tyrosine is effective at limiting cold-induced decreases in working memory, presumably by augmenting brain catecholamine levels, since tyrosine is a precursor for catecholamine synthesis. The effectiveness of tyrosine for preventing cold-induced decreases in physical performance has not been examined. This study evaluated the effect of tyrosine supplementation on cognitive, psychomotor, and physical performance following a cold water immersion protocol that lowered body core temperature. Fifteen subjects completed a control trial (CON) in warm (35 °C) water and two cold water trials, each spaced a week apart. Subjects ingested an energy bar during each trial; on one cold trial (TYR) the bar contained tyrosine (300 mg/kg body weight), and on the other cold trial (PLB) and on CON the bar contained no tyrosine. Following each water immersion, subjects completed a battery of performance tasks in a cold air (10 °C) chamber. Core temperature was lower ( p = 0.0001) on PLB and TYR (both 35.5 ± 0.6 °C) than CON (37.1 ± 0.3 °C). On PLB, performance on a Match-to-Sample task decreased 18% ( p = 0.02) and marksmanship performance decreased 14% ( p = 0.002), compared to CON, but there was no difference between TYR and CON. Step test performance decreased by 11% ( p = 0.0001) on both cold trials, compared to CON. These data support previous findings that dietary tyrosine supplementation is effective for mitigating cold-induced cognitive performance such as working memory, even with reduced core temperature, and extends those findings to include the psychomotor task of marksmanship.

A Meta-Analysis of Performance under Thermal Stress

The goal of this work was to perform a quantitative review of temperature effects on human performance, with the aim of advancing both theory and practice. Meta-analytic methods were applied to the available literature on thermal stress and performance. Two-hundred-ninety-one references were collected resulting in forty-nine publications that met selection criteria. These studies provided 528 effect sizes. Analyses revealed an overall detrimental effect of temperature on performance. Effect-size for heat was comparable to that for cold temperatures. Temperature effects were task dependent, that is cognitive performance was least affected by thermal stress, while both psychomotor and perceptual task performance were degraded to a greater degree. Other moderating variables were identified and observed to influence the effect of thermal stress. Although the results clearly indicate more empirical research is necessary to achieve more accurate estimates, the current study provides initial effect-size estimates that should be considered when designing human-machine systems.

Ramelteon

Ramelteon is a novel MT1 and MT2 melatonin receptor selective agonist recently approved for insomnia treatment. Most approved insomnia medications have potential for abuse and cause motor and cognitive impairment. To evaluate the potential for abuse, subjective effects, and motor and cognitive-impairing effects of ramelteon compared with triazolam, a classic benzodiazepine sedative-hypnotic drug. In this double-blind crossover study, each participant received oral doses of ramelteon (16, 80, or 160 mg), triazolam (0.25, 0.5, or 0.75 mg), and placebo during approximately 18 days. All participants received each treatment on different days. Most outcome measures were assessed at 0.5 hours before drug administration and repeatedly up to 24 hours after drug administration. Residential research facility. Fourteen adults with histories of sedative abuse. Subject-rated measures included items relevant to potential for abuse (eg, drug liking, street value, and pharmacological classification), as well as assessments of a broad range of stimulant and sedative subjective effects. Observer-rated measures included assessments of sedation and impairment. Motor and cognitive performance measures included psychomotor and memory tasks and a standing balance task. Compared with placebo, ramelteon (16, 80, and 160 mg) showed no significant effect on any of the subjective effect measures, including those related to potential for abuse. In the pharmacological classification, 79% (11/14) of subjects identified the highest dose of ramelteon as placebo. Similarly, compared with placebo, ramelteon had no effect at any dose on any observer-rated or motor and cognitive performance measure. In contrast, triazolam showed dose-related effects on a wide range of subject-rated, observer-rated, and motor and cognitive performance measures, consistent with its profile as a sedative drug with abuse liability. Ramelteon demonstrated no significant effects indicative of potential for abuse or motor and cognitive impairment at up to 20 times the recommended therapeutic dose and may represent a useful alternative to existing insomnia medications.

Impact of Auditory and Visual Distractors upon Manual Assembly Task Learning among Older Workers with Different Levels of Spatial Reasoning and Field Dependence

We examined the impact of age upon learning a manual assembly task in the presence of visual and auditory distractors in males and females ranging in age between 18 and 65 years. Task learning, as measured by time to asymptote as well as error rate. Both metrics were affected by distractors when both auditory and visual distraction loads were present, and only in older subjects who possessed low spatial reasoning ability. Older subjects who possessed excellent spatial reasoning capability performed competitively with younger subjects. Recommendations for use of spatial reasoning and field dependence in future aging-related psychomotor task learning research are provided and practical use of these findings are discussed.

The acute effects of d-amphetamine and methamphetamine on attention and psychomotor performance

It is not clear how the deleterious effects of amphetamines on driving performance are mediated in terms of select cognitive processes. The current three separate experiments assessed the acute effects of an oral dose of either 0.42-mg/kg d-amphetamine, d,l-methamphetamine and d-methamphetamine on driving-related cognitive functions in a total of 60 healthy non-fatigued adults. Three separate repeated measures counterbalanced, double-blind, placebo-controlled designs were employed in which 20 volunteers completed two treatment conditions, either d-amphetamine, d,l-methamphetamine or d-methamphetamine and placebo. Performance was assessed on a range of attentional, psychomotor and perceptual speed tasks. Mean blood concentrations at 120-, 170- and 240-min postdrug administration were 83, 98 and 96 ng/ml, respectively, for d-amphetamine, 90, 95 and 105 ng/ml, respectively, for d,l-methamphetamine and 72, 67 and 59 ng/ml, respectively, for d-methamphetamine. The amphetamines, in general, improved various aspects of attention (Digit Vigilance, Digit Symbol Substitution Test and Movement Estimation Performance) with some evidence to suggest possible enhancement in psychomotor functioning (Tracking ability) and perceptual speed (Inspection Time). The current series of studies primarily provides evidence of low-level amphetamine-related enhancement of function; however, it also provides evidence of less conservative movement estimation that might contribute to amphetamine-related road fatalities.

The role of alarm signal duration as a cue for alarm validity

Researchers have isolated several variables that moderate the degrading effects of alarm mistrust on alarm reactions. We examined how alarm duration influences reactions to alarms of varying true alarm rates. In Experiment one, 45 psychology students performed a complex psychomotor task while reacting to an alarm system generating short- and long-duration signals. We predicted that participants would consider long-duration alarms more valid and would respond more to them despite the true alarm rate. Results supported both expectations. In addition to these findings, participants believed that true alarm rate influenced their response decisions more than duration even though true alarm rate did not affect actual response frequency. In Experiment two, 40 students reacted to short- and long-duration alarms originating from unique systems. Results showed some participants relied on duration, whereas others used true alarm rate, responded extremely, or combined strategies. Overall, results suggest signal duration is an important influence, but that increased task complexity may lead operators to adopt other reaction strategies.

Risk assessment and human performance modelling: the need for an integrated systems approach

One of the difficulties in completing scientific experiments aboard the International Space Station (ISS) is anticipating all of the effects of the operational environment on the procedural sequences. Human Performance Modelling (HPM) and Probabilistic Risk Assessment (PRA)-like approaches could together generate such predictions for the space life sciences experimentation application domain. An informal risk assessment was completed through Subject Matter Expert (SME) interviews on procedural completion and potential for erroneous performance. The results suggested there would be significant differences in the performance and risk of completing a series of experiments sequentially as compared to completing the experiments in parallel. As a result, an initial HPM was developed to test predictions of simulated operator workload for a complex space-related biological experiment and the risk of error. Two procedural sequences are analysed, which highlight different human performance profiles that raise risks, or vulnerabilities, in physical, cognitive and psychomotor performance and task times. Future efforts need to build on these findings to include a comprehensive PRA process computationally linked to performance predictions generated from HPMs.

Fast Psychomotor Functioning in Anorexia Nervosa: Effect of Weight Restoration

In a previous study young seriously underweight anorexia nervosa (AN) patients in the early phase of treatment were found to react faster in psychomotor tasks. To further understand this finding we studied the impact of weight restoration on the performance of AN patients in drawing and copying tasks. A group of 17 female AN patients, aged 14 to 25, was compared with 17 healthy controls, matched for sex, age and educational level. Patients were tested when severely underweight and after weight restoration. Control subjects were also tested twice. Using computerized recording and analysis of writing and drawing behavior, reaction times and drawing times were derived, while cognitive and motor demands were manipulated. Overall, AN patients showed shorter reaction times in copying tasks and shorter drawing time in the drawing task than normal controls, and this pattern persisted after weight restoration. No significant group (AN vs. controls) by session (test vs. retest) effect emerged. The finding of a consistent pattern of shorter reaction and drawing times in AN patients before and after weight restoration is compatible with a personality characteristic of perfectionism and overachievement in AN patients. The authors would like to thank Leen Gielen for her help in applying the tests and preparing the data.

The effects of self‐administered alcohol‐induced ‘hangover’ in a naturalistic setting on psychomotor and cognitive performance and subjective state

To examine in as naturalistic a setting as possible whether having an alcohol-induced 'hangover' impairs psychomotor and cognitive performance. The sample consisted of 71 male and female social drinkers who were tested twice, once at baseline and once after exposure to the study condition. They were randomized into a control group who returned for testing on a prearranged date (n = 33), and a group who were instructed to make arrangements to return the day after a self-determined heavy drinking session (n = 38). Of the 'hangover' group, 13 participants still had a blood alcohol concentration of >1 mg/100 ml at the time of testing and these were analysed separately. All participants were students. Psychomotor performance was assessed by means of a battery of psychomotor tasks, rate of information processing was tested by the Speed and Capacity of Language Processing Test (SCOLP) and subjective state was assessed by questionnaire measures. All participants in the 'hangover' group reported subjective and physical symptoms of hangover on the second testing session. Performance was significantly impaired on the hits-key components of the vigilance task, was less accurate on the primary and secondary reaction time tasks and showed greater dispersion in range of ability for participants in the 'acute and hangover' compared to 'control'. Probe memory revealed no significant group effect. Ratings of subjective state revealed significant group differences for the variables 'ability to drive', 'concentrate' and 'react quickly' as well as 'tiredness'. There were no group differences for performance on the SCOLP. Hangover had negative effects on self-reported subjective and physical state and subtle effects on performance.

Diazepam Tolerance Effects on Vestibular Function Testing, Part II: Vestibulo-Ocular Reflex Parameters during Rotational Testing

The purpose of this prospective study was to determine whether clinical doses of diazepam (DZ; 10 mg/d) administered for 14 days result in tolerance as measured by the sinuosidal harmonic acceleration (SHA) rotational test. It has been shown that repeated dosing with DZ leads to accumulation and tolerance in outcome measures that assess memory, sedation, and psychomotor tasks. In a double-blinded, repeated-measures design, 30 normal male subjects who ranged in age from 20 to 36 years were randomly assigned to a placebo group or a DZ group and participated in 6 SHA rotational sessions over a 2-week period. Analysis of drug-placebo differences in percent change from baseline was performed with a 1-way analysis of variance. Vestibulo-ocular reflex gain and phase frequencies at 0.01, 0.02, 0.04, and 0.08 Hz were significant (p < .05) for treatment group. No significant effect was observed for gain and phase frequency at 0.16 Hz--a finding that indicates selective effects on different central nervous system mechanisms. There was no statistical significance for time. Clinically, the DZ subjects' scores remained within the normal ranges for vestibulo-ocular phase and gain, suggesting that patients in whom drug cessation is problematic may not have to discontinue DZ before testing with the SHA rotational system.

The Role of Anxiety on Novices' Rifle Marksmanship Performance

In this study we examined the role of anxiety on novices' performance on the psychomotor task of rifle marksmanship. The stages-of-skill-development model suggests that aptitude influences performance while learning a skill; however, the model does not address the role of affect. Assessments for state anxiety and state worry were administered to 42 novice shooters. Aptitude and state worry predicted shooting performance (r = .67) comparable to more direct psychomotor measures used in prior research. Incremental validity analyses showed that aptitude accounted for 11% of the variance, and state worry explained an additional 34% above and beyond aptitude. The use of noncognitive assessments can broaden the understanding of skilled performance. Although aptitude influences learning a skill, it appears that novice shooters' performance is also influenced by affective states such as anxiety.

Informing Accessible Design Through Selfreported Quality of Visual Health

This study investigates the potential utility of the VFQ-25 as an alternative to clinically acquired measures of visual function for investigations of computer-based performance. While clinical measures of visual function have been used as predictors of performance on psychomotor tasks for people with impaired vision, the VFQ-25 represents a low cost, easy-to-administer alternative. In this study, participants with Age-related Macular Degeneration and controls responded to the VFQ-25 and completed a drag-and-drop task with different feedback modalities. Based on VFQ scores, a hierarchical clustering algorithm was used to generate five distinct participant groups. Statistical comparisons of performance between the groups under each feedback condition confirmed the efficacy of the VFQ-25 as a tool for classifying user interaction. Consistent with previous studies comparing performance based solely on visual acuity, these results encourage the use of the VFQ-25 in research and design in circumstances that are not conducive to gathering clinically acquired measures.

Neurobehavioral Changes in Taiwanese Lead-Exposed Workers

The dysfunction of the central nervous system (CNS) caused by lead exposure was evaluated. Workers who have been exposed to lead for at least 3 years and have been informed of having elevated blood lead levels (BLLs) were recruited. According to their current BLLs, 33 and 28 males were assigned to the medium (40-80 microg/dL) and low (<40 microg/dL) BLLs groups, respectively. Sixty-two nonexposed healthy men served as the control group. Their neurobehaviors were examined by a computerized evaluation system. Significantly impaired neurobehavioral functions were shown in the medium BLLs group, which included slow performance of psychomotor tasks, impaired processing of visual-spatial information, reduced memory and learning functions, low performance accuracy, slow execution of responses, and poor attentional control. Subtle CNS dysfunction could be detected from lead-exposed workers who have no obvious neurologic and cognitive deficits.

Performance and alertness effects of caffeine, dextroamphetamine, and modafinil during sleep deprivation

Stimulants may provide short-term performance and alertness enhancement during sleep loss. Caffeine 600 mg, d-amphetamine 20 mg, and modafinil 400 mg were compared during 85 h of total sleep deprivation to determine the extent to which the three agents restored performance on simple psychomotor tasks, objective alertness and tasks of executive functions. Forty-eight healthy young adults remained awake for 85 h. Performance and alertness tests were administered bi-hourly from 8:00 hours day 2 to 19:00 hours day 5. At 23:50 hours on day 4 (after 64 h awake), subjects ingested placebo, caffeine 600 mg, dextroamphetamine 20 mg, or modafinil 400 mg (n=12 per group). Performance and alertness testing continued, and probe tasks of executive function were administered intermittently until the recovery sleep period (20:00 hours day 5 to 8:00 hours day 5). Bi-hourly postrecovery sleep testing occurred from 10:00 hours to 16:00 hours day 6. All three agents improved psychomotor vigilance speed and objectively measured alertness relative to placebo. Drugs did not affect recovery sleep, and postrecovery sleep performance for all drug groups was at presleep deprivation levels. Effects on executive function tasks were mixed, with improvement on some tasks with caffeine and modafinil, and apparent decrements with dextroamphetamine on others. At the doses tested, caffeine, dextroamphetamine, and modafinil are equally effective for approximately 2-4 h in restoring simple psychomotor performance and objective alertness. The duration of these benefits vary in accordance with the different elimination rates of the drugs. Whether caffeine, dextroamphetamine, and modafinil differentially restore executive functions during sleep deprivation remains unclear.