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Measurement and scaling of workload in complex performance.

Two groups of paid male volunteers (Groups I, N = 51, tested with identical schedules on two successive days; Group II, N = 43, tested on one day only) performed over nine intervals on various combinations of the six tasks of the CAMI Multiple Task Performance Battery. Two of the tasks involved monitoring static (lights) and dynamic (meters) processes, and four more-active tasks involved mental arithmetic, elementary problem solving, pattern identification, two-dimensional compensatory tracking. Five of the nine intervals provided different complex tasks consisting of concurrent monitoring tasks and two of the active tasks. Other trials provided data on the single active tasks as well as the combined monitoring tasks. The results indicated that all performance measures--a total of 12 for the six tasks--varied significantly as a function of the different task-combination conditions. A standard psychological scaling technique (Thurstone Case V) was applied to the monitoring data (response times for green and red lights, and for meter monitoring) to develop an index of workload for the five complex task combinations. Since better performance was presumed to indicate a lower workload, workload was inferred to increase as performance declined across conditions. The best performances, which were assigned scale values of 0, were found to be associated with single-task performances, as expected. Scale values for the complex task-combination conditions were found to be consistent between groups and between the two days of testing of Group I (r's of 0.947 to 0.993). Although the scale values are specific to the task and task-combination conditions employed, the scaling-procedure application shows promise for cases in which quantitative measures of performance can be acquired with moderately large samples of subjects (N's greater than 50).

Adolescent

Effects of antidepressant administration on physical performance and perceived exertion in athletes: systematic review and meta-analysis.

INTRODUCTION: Antidepressants are commonly prescribed in athletes with depressive disorders, yet their potential effects on physical performance and perceived exertion remain unclear, and existing evidence is limited and inconsistent. AIM: This systematic review and meta-analysis aimed to evaluate the effects of antidepressant use on objective physical performance and perceived exertion in athletes. METHOD: A systematic literature search was conducted in PubMed, the Cochrane Library, Web of Science, and SPORTDiscus through March 2025. Eligible studies were randomised controlled trials (RCTs) published in English that enrolled elite, competitive, or recreational athletes; compared antidepressant administration with placebo or no treatment; and reported at least one objective or subjective performance-related outcome. Meta-analyses were performed using random-effects models, and pooled mean differences with 95% confidence intervals (CI) were calculated. This systematic review and meta-analysis was registered in PROSPERO (CRD420251123740). RESULTS: Ten crossover RCTs involving 99 male athletes were included. Interventions included a norepinephrine reuptake inhibitor (reboxetine), a norepinephrine-dopamine reuptake inhibitor (bupropion), and selective serotonin reuptake inhibitors (fluoxetine or paroxetine). Acute antidepressant administration was associated with a small increase in rating of perceived exertion (RPE; mean difference 0.52 points on the Borg 6-20 scale, 95% CI 0.01-1.04; p&#x2009;<&#x2009;0.05). No significant overall effects were observed for time-trial performance, mean power output, heart rate or blood lactate. However, subgroup analyses showed that reboxetine significantly impaired time-trial performance (mean difference 3.62&#xa0;min, 95% CI 0.18-7.06; p&#x2009;<&#x2009;0.05) and reduced mean power output (mean difference&#x2009;-&#x2009;19.97 W, 95% CI&#x2009;-&#x2009;36.87 to&#x2009;-&#x2009;3.06; p&#x2009;<&#x2009;0.05). CONCLUSION: Short-term antidepressant administration in athletes was associated with a small increase in perceived exertion, without consistent impairment in objective physical performance. As the current evidence derives exclusively from male athletes and acute exposure, further research should clarify its relevance to female athletes and to longer-term antidepressant treatment in athletes with depressive disorders.

Humans

Alpha-2 adrenergic agonists decrease distractibility in aged monkeys performing the delayed response task.

With advancing age, monkeys become impaired on a test of spatial working memory, the delayed response task, and show increased susceptibility to interference from irrelevant stimuli (Bartus and Dean 1979). Alpha-2 adrenergic agonists such as clonidine and guanfacine have been shown to improve the delayed response performance of aged monkeys under standard testing conditions (e.g. Arnsten et al. 1988). The current study examined whether these drugs could protect the delayed response performance of aged monkeys when irrelevant stimuli were presented during the delay intervals. Aged monkeys were tested on the variable delayed response task with short delays to minimize memory demands and optimize performance on control (no interference) sessions. During interference sessions, distractors were presented during the delays on 9 of the 30 trials ("distractor" trials). If the aged monkeys had been pretreated with saline, performance was significantly disrupted by the irrelevant stimuli compared to matched saline control sessions. This impairment was not only evident on the 9 distractor trials, but on the 21 remaining "nondistractor" trials as well. However, if the aged monkeys had been pretreated with clonidine or guanfacine, performance was not impaired on the interference sessions. This beneficial effect of the alpha-2 agonists was most apparent on the nondistractor trials. Guanfacine was able to decrease the harmful effects of distraction without any apparent sedative side effects. Co-administration of the alpha-2 antagonists idazoxan or SKF104078 with clonidine blocked the protective effects of the agonist on delayed response performance, consistent with actions at alpha-2 adrenergic receptors. These findings suggest that alpha-2 agonists improve delayed response performance, at least in part, by helping to protect memory from irrelevant stimulation. Clonidine is already used in the treatment of Attention Deficit Disorder, and the current data suggest that guanfacine may also be useful in this regard.

Adrenergic alpha-Agonists

Applicability of the hierarchical scales of the Tufts Assessment of Motor Performance for school-aged children and adults with disabilities.

The relative difficulty of motor performance tasks for school-aged children and adults with physical disabilities within a standardized motor performance test was examined. The Tufts Assessment of Motor Performance (TAMP) was administered to 69 children (ages 6-18 years, X = 12.1, SD = 3.9) and 137 adults (ages 19-83 years, X = 46.7, SD = 20.0) with neurological and musculoskeletal impairments. The purpose of the study was to determine whether the hierarchical scales of the motor performance tasks between the pediatric and adult disability samples were congruent. Correlations of task difficulty calibrations (r = .76; P less than .01) and task rank ordering (rho = .76; P less than .01) were moderately high and positive between pediatric and adult subjects. Significant age-group differences emerged in relation to a number of individual motor performance tasks. In general, mobility and ambulation tasks were relatively easier for children, whereas manipulation tasks were relatively easier for adults. The data suggest a strong similarity in the overall pattern of motor performance task difficulty for children and adults. The results support the use by physical therapists of two parallel versions of the TAMP to describe the motor performance of adults and school-aged children with physical disabilities.

Activities of Daily Living

Correlation of eye color on self-paced and reactive motor performance.

Researchers continue to examine the distinctiveness of motor performance by dark- versus light-eyed individuals. Dark-eyed individuals generally perform better at reactive type tasks (boxing, hitting a ball, defensive positions in football, rotary pursuit), while light-eyed individuals perform better at self-paced tasks (bowling, golf, pitching baseballs). Subjects performed two tasks, rotary pursuit and ball tossing (with light and dark background). Eye color (light or dark) and accuracy of performance were recorded for each subject. No significant difference was found between eye color and performance on the pursuit rotor (reactive activity). A significant difference was found between men's and women's performance in throwing a ball (self-paced activity) at a light-colored background.

Adult

Empirical separation of physiologic and expected effects of alcohol on complex perceptual motor performance.

The role of expectancy in producing perceptual motor-performance deficits following alcohol consumption was investigated in a 2 X 2 factorial experiment. Forty male normal drinkers (1) either were or were not administered 0.414 g ethanol/kg body weight and (2) either were or were not instructed they were consuming an alcoholic beverage (regardless of actual beverage content). Performance on a divided-attention task requiring simultaneous pursuit rotor tracking and choice reaction-time responding provided the main dependent measures. Alcohol disrupted tracking performance and interacted with instructions regarding beverage content to influence choice reaction-time performance. Results confirmed previous reports of divided-attention task performance deficits induced by a low alcohol dose, but, more importantly, indicated that subjects' expectancies also influence performance levels. These findings demonstrate the importance of controlling for expectancy effects in alcohol research, and suggest that alcohol and expectancy may influence perceptual motor performance through different processes.

Adult

Neuropsychological significance of variations in patterns of academic performance: verbal and visual-spatial abilities.

Forty-five 9- to 14-year-old children with learning disabilties whose WISC Full Scale IQs fell within the range of 86-114 were divided into three groups on the basis of their patterns of reading, spelling, and arithmetic achievement. Group 1 was composed of children who were uniformly deficient in reading, spelling, and arithmetic; children in Group 2 were relatively adept at arithmetic as compared to their performance in reading and spelling; Group 3 was composed of children whose reading and spelling performances were average or above, but whose arithmetic performance was relatively deficient. The performances of these children on 16 dependent measures were compared. The performances of Groups 1 and 2 were superior to that of Group 3 on measures of visual-perceptual and visual-spatial abilities; Group 3 performed at a superior level to that of Groups 1 and 2 on measures of verbal and auditory-perceptual abilities. The results are discussed in terms of the relationships between varying patterns of academic abilities and patterns of brain-related behaviors, and the nature of the neuropsychological abilities that may limit performance on arithmetic calculation tasks.

Achievement

Measuring the predictive performance of computer-controlled infusion pumps.

Current measures of the performance of computer-controlled infusion pumps (CCIPs) are poorly defined, of little use to the clinician using the CCIP, and pharmacostatistically incorrect. We propose four measures be used to quantitate the performance of CCIPs: median absolute performance error (MDAPE), median performance error (MDPE), divergence, and wobble. These measures offer several significant advantages over previous measures. First, their definitions are based on the performance error as a fraction of the predicted (rather than measured) drug concentration, making the measures much more useful to the clinician. Second, the measures are defined in a way that addresses the pharmacostatistical issue of appropriate estimation of population parameters. Finally, the measure of inaccuracy, MDAPE, is defined in a way that is consistent with iteratively reweighted least squares nonlinear regression, a commonly used method of estimating pharmacokinetic parameters. These measures make it possible to quantitate the overall performance of a CCIP or to compare the predictive performance of CCIPs which differ in either general approach (e.g., compartmental model driven vs. plasma efflux approach), pump mechanics, software algorithms, or pharmacokinetic parameter sets.

Adult

Effect of menstruation on academic performance among college women.

Many studies report that women's performance and affective patterns fluctuate with their menstrual cycle. Poor mental performance is generally more common during menstruation and for several days prior to onset. Research on academically advanced women, however, has shown that their scholastic performance is less likely to exhibit the usual menstrual decline. Presumably, they are motivated enough to exert a compensatory effort on "off-days." Thus the current research was designed to test whether, among college women, academic performance fluctuates with the menstrual cycle. The academic performance of volunteers in and introductory college psychology course was followed. Biweekly course tests were used to measure performance. The subjects filled out menstrual calendars, indicated their SAT scores, and answered questions from a standardized test of academic motivation. Following the convention of past research, the "paramenstruum" (the time of menstrual stress) was defined to be the 4 days prior to onset and the first 4 days of menstruation. The other days in the cycle comprise the "intermenstruum." On all eight tests, the difference between paramenstrual and intermenstrual performance (adjusted for aptitude and motivation) was insignificant.

Achievement

Evaluating the impact of modeling choices on the performance of integrated genetic and clinical models.

PURPOSE: The value of genetic information for improving the performance of clinical risk prediction models has yielded variable conclusions. Many methodological decisions have the potential to contribute to differential results. We performed multiple modeling experiments integrating clinical and demographic data from electronic health records with genetic data to understand which decisions may affect performance. METHODS: Clinical data in the form of structured diagnostic codes, medications, procedural codes, and demographics were extracted from 2 large independent health systems, and polygenic risk scores (PRS) were generated across all patients of European ancestry with genetic data in the corresponding biobanks. Crohn's disease was studied based on its substantial genetic component, established electronic health records-based definition, and sufficient prevalence for training and testing. We investigated the impact of choices regarding the PRS integration method, training sample, model complexity, and performance metrics. RESULTS: Overall, our results showed that including PRS resulted in higher performance, but this gain was only robust in situations with limited clinical information. We found consistent performance increases from more compute-intensive models, such as random forest, but the impact of other decisions varied by site. CONCLUSION: This work highlights the importance of considering methodological decision points in interpreting the impact of PRS on prediction performance in clinical models.

Humans

Understanding the sources of performance in deep drug response models reveals insights and improvements.

MOTIVATION: Anti-cancer drug response prediction (DRP) using cancer cell lines (CLs) is crucial in stratified medicine and drug discovery. Recently, new deep learning models for DRP have improved performance over their predecessors. However, different models use different input data types and architectures making it hard to find the source of these improvements. Here we consider published DRP models that report state-of-the-art performance predicting continuous response values. These models take chemical structures of drugs and omics profiles of CLs as input. RESULTS: By experimenting with these models and comparing with our simple baselines, we show that no performance comes from drug features, instead, performance is due to the transcriptomics CL profiles. Furthermore, we show that, depending on the testing type, much of the current reported performance is a property of the training target values. We address these limitations by creating BinaryET and BinaryCB that predict binary drug response values, guided by the hypothesis that this reduces the noise in the drug efficacy data. Thus, better aligning them with biochemistry that can be learnt from the input data. BinaryCB leverages a chemical foundation model, while BinaryET is trained from scratch using a transformer-type architecture. We show that these models learn useful chemical drug features, which is the first time this has been demonstrated for multiple testing types to our knowledge. We further show binarizing the drug response values causes the models to learn useful chemical drug features. We also show that BinaryET improves performance over BinaryCB, and the published models that report state-of-the-art performance. AVAILABILITY AND IMPLEMENTATION: Code is available from https://github.com/Nik-BB/Understanding_DRP_models.

Humans

Performance studies with diazepam and its hydroxylated metabolites.

1 Visuo-motor coordination has been used to study the immediate and residual effects of benzodiazepines on performance in man. The technique provides dose and time response data related to the decrement and the persistence of impaired performance. 2 With the overnight ingestion of flurazepam hydrochloride 30 mg and nitrazepam 10 mg, performance was impaired to 16 h and, at least, 19 h, respectively. Performance was not impaired after the overnight ingestion of diazepam, 5 and 10 mg, temazepam 10, 20 and 30 mg or oxazepam 15 and 30 mg. However, with temazepam 30 mg there was a trend toward impaired performance,, and with oxazepam 45 mg, performance was impaired 10 h after ingestion. With morning ingestion, coordination was impaired 0.5 and 2.5 h after diazepam 10 mg, at 0.5 h after temazepam 20 mg, and after oxazepam 30 mg at 2.5 and 4.5 hours. 3 The studies suggest that diazepam 5-10 mg, temazepam 10-20 mg and oxazepam 15-30 mg may be of use in the management of sleep disturbance when impaired performance the next day is to be avoided.

Barbiturates

A comparison of the performance of three multiple choice question papers in obstetrics and gynaecology over a period of three years administered at five London medical schools.

Four, and later five, of the medical schools in the one multiple choice question (MCQ) paper in Obstertrics and Gynaecology to their students at the end of the Obstetrics and Gynaecology courses. The paper was amended twice after intervals of approximately 12 months. The results showed differences in performance between the five schools on questions and alternatives within questions, which were common to all editions of the paper (the "short" paper). These differences were also shown in the first two editions of the full paper (the "long" paper), but were not apparent in the third. There was a significant improvement in performance from the first to the second paper edition of the long by approximately 11%, but this was reversed from the second to the third edition, where there was a significant decrease in performance by approximately 4%. We cannot here exclude the possibility that this decrease in the third edition has resulted from sample bias. The rank order of the schools may result from differences in methods of teaching. It seems that such relative performance between London medical schools in contributed to by the differences in course legnth and by the occurence of mid-course test. It appears also that student performance in any of the schools has not been uniform over the period of the study, there being a peak during the period when the second edition of the paper was used. Variations in student selection occuring between schools may effect some of these differences. There was also a marked difference in students' performance between Obstetrics and Gynaecology. The short papers appeared easier than the full papers. Whilst this may due to the greater clarity of phrasing for the questions of the short paper, we also believe the subject matter of the short paper may be more relevant. A distinct effect could also be shown, over the period, due to improvements in the wording of the questions. It is possible that students perform better at Obstetrics than at Gynaecology.

Curriculum

Threshold perception performance with computed and screen-film radiography: implications for chest radiography.

Images of a phantom obtained with computed radiography and standard screen-film imaging were compared to evaluate observer threshold perception performance with a modified contrast-detail technique. Optimum exposure necessary for performance with the imaging plate technique to match that with screen-film techniques was determined, as was comparative performance with variation in kilovoltages, plate type, spatial enhancement, and hard-copy interpolation method. It was found that computed radiography necessitates about 75%-100% more exposure than screen-film radiography to optimally match performance with Ortho-C film with Lanex regular or medium screens (Eastman Kodak, Rochester, NY) for detection of objects 0.05-2.0 cm in diameter. However, only minimal loss of detection performance (approximately 10% overall) was experienced if standard screen-film exposures were used with computed radiography. Little change in observer performance was found with variation in plate type, spatial enhancement, or method of hard-copy interpolation. However, perception performance with computed radiographic images was better at lower kilovoltages.

Humans

Biological and performance variables in relation to age in male and female adolescent athletes.

To observe the cross-sectional nature of the effect of age, height, and body mass on motor performance during adolescence (13-18 years), 103 boy and 65 girl athletes were measured for motor performance and anthropometric variables. Motor performances included tests of strength, muscular endurance, flexibility, aerobic capacity, anaerobic power, speed, and agility. Anthropometric determinations included height, body mass, lean body mass, %fat, and somatotype. Boys were significantly different from girls in all measurements except endomorphy, while girls were significantly superior to boys only in flexibility. Physical maturation, as reflected by height and body mass, was a major contributor to increases in motor performance. Somatotype did not differ greatly across the age groups. Boys were significantly more mesomorphic than girls, while girls were significantly more ectomorphic than boys. Higher %fat and more endomorphy were significantly related to poorer performance for relative aerobic capacity, 40-yd dash, and agility in boys but only for upper body muscular endurance in girls. Mesomorphy had higher relationships with performance variables among boys than among girls. Growth would appear to contribute significantly to enhanced motor performance with age, and its effect may be different in boys than in girls.

Adipose Tissue

Establishing and maintaining performance claims. A manufacturer's viewpoint.

Performance claims are the vehicle by which a manufacturer communicates the analytic capabilities of its methods to laboratory users and to regulatory agencies. Claims describe the expected performance of an analytic system. To be useful, claims must be meaningful, achievable, and verifiable. To ensure consistent interpretation, they must be stated in clear, unambiguous terms. There are no specific guidelines for stating claims. Consequently, comparing the performance of one system to another is difficult. Claims fall into three categories: clinical utility, analytical performance, and boundary conditions. This article focuses on the three basic analytical performance characteristics, precision, accuracy, and specificity, and describes how they are established, validated, maintained, and monitored by manufacturers and how they can be verified by end users. Precision claims describe the inherent variability of the system. They differ in the components of variance included, ranging from the short-term variables within a single run to the long-term variables experienced over time, such as lot changes, calibrations, instrument drift, and environmental fluctuations. Precision may be stated either as typical user experience or as the minimum performance expected. Accuracy claims describe the degree to which the results will approximate the true values. They are more difficult to establish and verify, given the lack of objective standards for many analytes. For this reason, few manufacturers make true accuracy claims, relying instead on comparisons with other marketed methods. A notable exception is cholesterol, for which a model reference system has been established to help laboratories ensure accuracy. External proficiency testing is handicapped by matrix effects from imperfect survey fluids. Specificity claims describe the method's freedom from interference and cross-reactivity. They are based on screening tests by the manufacturer, augmented by feedback from users. There are no agreed-on criteria for what constitutes clinically significant interference, and no consistent approach for disclosing interference information. The National Committee for Clinical Laboratory Standards, Villanova, Pa, is beginning to develop guidelines to promote greater consistency in performance claim statements.

Calibration

Impact of Muscle Quality on Muscle Strength and Physical Performance Beyond Muscle Mass or Diabetes Status.

BACKGROUND: Muscle quality, represented by myosteatosis, is recognized as an important factor in sarcopenia. In this study, we aimed to determine the associations between myosteatosis, muscle strength and physical performance among the elderly South Korean population. METHODS: We included 1440 participants (mean age 62.7&#x2009;&#xb1;&#x2009;6.2&#x2009;years) from the Korean Genome and Epidemiology Study (KoGES). Based on the computed tomography attenuation of mid-thigh imaging, the total muscle area (TMA), normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA) and inter-intramuscular adipose tissue (IMAT) and its indices were used to evaluate myosteatosis. Muscle strength was evaluated using hand grip strength, whereas physical performance was evaluated through 4-m gait speed, a 30-s sit-to-stand test and 2-min walking test. RESULTS: Of the 1440 patients, 51.5% were women, and 37.2% had diabetes. With aging, the LAMA index gradually increased, and the NAMA index gradually decreased in both men and women (p for trend <&#x2009;0.001). The NAMA index was positively associated, whereas the LAMA and IMAT indices were negatively associated with muscle strength and physical performance after adjusting for age and sex. Higher tertiles of the NAMA index were consistently associated with improved physical performance across all appendicular skeletal muscle tertiles. The relationship between the NAMA index or LAMA index and muscle strength and physical performance did not differ according to diabetic status. Regular exercise was associated with a higher NAMA index and a lower LAMA index in the non-diabetic group; however, no significant difference in muscle quality was observed in the diabetic group in relation to exercise. CONCLUSIONS: Reduced myosteatosis was positively associated with greater muscle strength and better physical performance in both men and women, regardless of muscle mass or diabetes status; improving myosteatosis may be a therapeutic target for the prevention of sarcopenia.

Humans

Effects of loratadine and cetirizine on actual driving and psychometric test performance, and EEG during driving.

Sixteen healthy male and female volunteers took part in a 6-way, double-blind cross-over trial to compare the effects of single doses of cetirizine 10 mg, loratadine 10 mg and placebo, with and without alcohol (0.72 g.kg-1, lean body mass). Performance was measured in two repetitions of a psychometric test battery, and a standard, over-the-road driving test. EEG was also measured during driving. Alcohol significantly affected almost every performance measure and altered the EEG energy spectrum during driving whilst the blood concentrations declined from 0.37 to 0.20 mg.ml-1. The effects of cetirizine of on driving performance resembled those of alcohol. It caused the subjects to operate with significantly greater variability in speed and lateral position ('weaving' motion). The effects of alcohol and cetirizine appeared to be additive. Certain cetirizine-placebo differences in subjective feelings and test battery performance were also significant. Loratadine had no significant effect on any performance parameter. It was concluded that cetirizine, but not loratadine, generally caused mild impairment of performance after a single 10 mg dose.

Adult