Effectiveness of an ACT‐based rehabilitation program for the treatment of chronic fatigue: Results from a 12‐months longitudinal study

Acceptance and Commitment Therapy (ACT) is potentially effective for treating chronic fatigue. Given the paucity of studies on this topic, we aimed to assess long‐term trajectories of primary (fatigue, quality of life and functional abilities) and secondary outcomes (anxious and depressive symptoms) of an ACT‐based rehabilitation program for patients with chronic fatigue. Further, we examined if changes in potential process variables (psychological inflexibility, metacognitive beliefs, and cognitive and behavioral responses to symptoms) during ACT predicted change in all outcomes across follow‐up. One‐hundred ninety‐five workers on sick leave (mean age: 43.61 ± 9.33 years; 80.5% females) with a diagnosis of chronic fatigue were enrolled in a manualized, 3.5‐week intensive return‐to‐work rehabilitation program based on ACT. All completed a battery of questionnaires at pre‐, post‐treatment, 6 and 12 months follow‐up. We found significant longitudinal changes in most primary and secondary outcomes from pre‐ up to 12 months follow‐up. All process variables significantly decreased from pre‐ up to 12 months follow‐up, and pre‐to‐post changes in fear avoidance beliefs were most often associated with a greater change in outcomes across follow‐up. Depressive symptomatology showed a similar trajectory of change to fatigue, meaning that scores were correlated at each time point and tended to converge over time. This suggests that both symptoms influence each other substantially over a year following the treatment. Concluding, results lend support to the effectiveness of an ACT‐based rehabilitation program for patients with chronic fatigue and provide preliminary evidence for the role of process variables and depressive symptomatology on subsequent change in outcomes.     

Development of the 24-h rest-activity pattern in human infants

The development of the 24-h rest-activity pattern was investigated in human infants under naturalistic conditions as assessed by continuous actigraphy. Seven infants and their mothers were recorded for 4 (n=1), 6 (n=5) and 12 months (n=1) after birth. Periodogram analysis of rest-activity data was performed over consecutive 10-day intervals. A weak 24-h rest-activity pattern was already present in some infants during the newborn period. The magnitude of the 24-h component in individual periodograms increased across the first months following a saturating function. The time constants of fitted saturating exponential functions--reflecting the rate of development of the 24-h pattern--ranged from 49 to 110 days (n=6) indicating a large interindividual variability. Furthermore, intraindividual variation was observed; the magnitude of the 24-h rest-activity component showed fluctuations around the trend. Miniaturized actigraphs are ideal tools for long-term longitudinal monitoring of rest-activity behavior in infants.     

Sustained operations and military performance

A militarily realistic schedule is one that demands several days with only very limited opportunities for sleep, followed by several days without any opportunity for sleep. A trial was carried out to study the effects of total sleep deprivation following partial sleep deprivation. Twelve infantry soldiers, divided into two groups of six, took part in a 6-day trial in which the experimental group was scheduled for 1.5 h of sleep every 24 h for 3 days followed by 3 days in which no sleep was scheduled. The control group was scheduled to have 4 h of sleep every 24 h for 6 days. Following the sleep-deprivation period, unlimited sleep was permitted for both groups in a 40.25-h (1.7-day) rest period. Three of the six subjects in the experimental group completed the 152 h (6.3-day) trial; all six subjects in the control group completed the trial. On the last sleep-deprivation day, cognitive performance was 37% of the baseline value for the experimental group and 94% for the control group.     

Sleepiness and days of recovery

In the literature recovery after work is taken for granted – one has 16 h off between work bouts and one has 36 h off each weekend. However, the situation for those working irregular work hours may be quite different because of night work, long shifts, or long sequences of working days. Strictly speaking we don't have any scientific support for theories on how recovery days should be patterned. This paper, therefore, brings together data from a series of our own studies that involve irregular work hours, with the specific purpose of looking at the recovery process. The results show that for the average normal office week worker two days of recovery are normally sufficient. For those who work long shifts in long sequences three days are needed for normalization, whereas 12 h shifts in 2–3 day sequences seem not to cause accumulated fatigue. Interestingly, fatigue/sleepiness is often at its peak during the first day of recovery – not the last day of the working week. Air crew and oil rig workers take a longer time to recover, probably because of too much adjustment of the biological clock. As a rule, long haul air crew is usually much more fatigued than short haul crew during their days off, despite the fact that long haul flying is voluntary and opted for by those who fly it. Also train drivers are affected during their days off by their irregular work hours – in particular backwards rotating schedules seem to cause accumulation of fatigue. The results suggest that one day of recovery never is sufficient, two days usually is, whereas 3–4 days are necessary after periods of severely disturbed circadian rhythmicity.     

EXPLORING BLACK-WHITE SUBGROUP DIFFERENCES OF MANAGERIAL COMPETENCIES

This study investigates whether different job-relevant competencies vary in terms of Black-White subgroup differences exhibited. There were 633 participants (545 Whites, 88 Blacks) who completed a managerial assessment center that evaluated 13 competency dimensions across 8 assessment exercises. Participants also completed a cognitive ability test. The results suggest that subgroup differences vary by the content domain of the competency. As predicted, significant subgroup differences emerged for a majority of the more cognitively loaded competencies (e.g., judgment) while nonsignificant differences were associated with a majority of the less cognitively loaded competencies (e.g., human relations). Furthermore, when cognitive ability was controlled, 12 of 13 competency scores demonstrated incremental validity in predicting supervisory job performance ratings. In addition, competencies with greater cognitive load tended to more strongly predict cognitive aspects of job performance as compared to noncognitive aspects. However, competencies with less cognitive load did not differentially predict cognitive and noncognitive aspects of job performance.     

Exploration of the effects of task-related fatigue on eye-motion features and its value in improving driver fatigue-related technology

Mental fatigue has been lacked attention in developing eye-tracking fatigue detection system for drivers. However, it has great influence on eye movement which could account for the poor validity of current fatigue detectors only focusing on sleep-related fatigue. This work sought to investigate the influence of two types of task-related mental fatigue on eye movement by examining 8 saccade-based, 3 blink-based, and 1 pupil-based metrics. We propose that two types of task-related fatigue caused by cognitive overload and prolonged underload will induce different physiological responses to eye-motion features. Twenty participants completed a vigilance task before and after a 1-h driving with a secondary task in a virtual simulation environment, while forty participants, divided equally into two groups, finished the same task before and after a 1-h and 1.5-h monotonous driving. T-test was applied to analyse the eye-motion, subjective and vigilance data during vigilance task. We found that overload driving made drivers vigilance ability decrease. The eye metrics showed different changes in underload and overload scenario. The blink duration, the mean velocity of saccade and saccade duration increased after 1-h overload driving, while the pupil diameter decreased. However, none of those changes were observed in 1.5-h underload driving, but saccade duration had a significant increase. The fatigue response to heavy demands over short periods of driving is different from the lighter demands over long periods in terms of eye-motion metrics. Considering mental fatigue in designing an eye-tracking fatigue detection system could possibly improve its accuracy.     

Sleep deprivation and naps

It is important for military commanders to know the likely effects of a small amount of sleep under conditions of sustained operations. To this end, two laboratory-based experiments on naps were carried out. The first examined the effect of 2 h of sleep following 90 h of wakefulness. Ten infantrymen subjects were not told the scheduled length of their vigil, or that they would be allowed a nap at some stage, until a few hours before the 2-h nap. After 3 nights without sleep, the subjects’ average cognitive performance was 55% of the control values. During a test session immediately before the 2-h nap, performance improved by 30%, to 85% of control values, indicating the considerable effect that the incentive of knowing that a nap is imminent can have on even severely sleep-deprived subjects. In the second experiment, two groups, each of six infantrymen, took part in a 5-day trial; for one group, 4 h of uninterrupted sleep was scheduled and for the other, four l-h naps in each 24-h period. There were no significant differences in cognitive test scores or mood between the two groups. On the last experimental day, cognitive test and mood scores were not significantly different from baseline values for either group, indicating the utility of 4 h of sleep, either in one uninterrupted block or in four scheduled 1-h naps per 24 h.     

Psychological performance assessment via interactive voice response systems

Two experiments examined the feasibility of psychological assessment using interactive voice response (IVR) technology and the potential sensitivity of such assessments to alcohol and fatigue effects. In Experiment 1, 10 subjects performed a 12-min battery of six IVR-administered tasks, Monday through Friday, over 2 weeks. Minimal learning effects were evident during training. Repeated administrations indicated high test-retest reliabilities. In Experiment 2 (double-blind, alcohol/placebo crossover design), 7 subjects were tested every 2 h over a 24-h period during two experimental sessions (peak blood alcohol concentrations =80 mg/dL). Several IVR-administered tasks were sensitive to alcohol impairment, but not as sensitive as laboratory-based measures specifically designed to assess alcohol impairment. Little evidence for fatigue-related impairment was obtained. The results support optimism for the potential to assess psychomotor and cognitive functioning distally via telephony; however, further refinement and validation of the methods are needed.     

Salivary chromogranin-A as a marker of psychological stress during a cognitive test battery in humans

The purpose of the present study was to evaluate the salivary Chromogranin-A (CgA) response to the psychological stress induced by a cognitive test battery. The subjects were 14 healthy volunteers administered the cognitive test battery CogScreen Aeromedical Edition (CogScreen-AE). CogScreen-AE is a test of reaction time and fundamental cognitive ability in the assessment of aeroplane pilots. The subjects were given five batteries of the test (1st approximately 5th) on separate days with 2 week intervals. Saliva samples were collected at 20 min before the test (BASE), immediately before the test (PRE), in the middle of the test (MID), and 5 min after the test (POS) for each subject. The concentration of CgA was determined by enzyme-linked immunosorbent assay. ANOVA revealed a significant by time interaction (BASE, PRE, MID and POS) without a significant effect of battery interaction (1st, 2nd, 3rd, 4th and 5th). The CgA concentration increased at PRE (2.46 +/- 0.24 pmol.mg protein- 1) from BASE (1.19 +/- 0.10 pmol.mg protein- 1). CgA level remained increased in the MID (2.90 +/- 0.26 pmol.mg protein- 1) and remained high in the POS samples (2.81 +/- 0.23 pmol.mg protein- 1). Salivary CgA remained at basal levels during a control study over the same time course without exposure to CogScreen-AE. The changes in salivary CgA secretion as a result of exposure to a cognitive task may indicate psychological stress in humans.     

Cognitive performance in older adults with stable heart failure: Longitudinal evidence for stability and improvement

Cognitive impairment is prevalent in heart failure (HF), though substantial variability in the pattern of cognitive impairment is found across studies. To clarify the nature of cognitive impairment in HF, we examined longitudinal trajectories across multiple domains of cognition in HF patients using latent growth class modeling. 115 HF patients completed a neuropsychological battery at baseline, 3-months and 12-months. Participants also completed the Beck Depression Inventory-II (BDI-II). Latent class growth analyses revealed a three-class model for attention/executive function, four-class model for memory, and a three-class model for language. The slope for attention/executive function and language remained stable, while improvements were noted in memory performance. Education and BDI-II significantly predicted the intercept for attention/executive function and language abilities. The BDI-II also predicted baseline memory. The current findings suggest that multiple performance-based classes of neuropsychological test performance exist within cognitive domains, though case-controlled prospective studies with extended follow-ups are needed to fully elucidate changes and predictors of cognitive function in HF.     

Reliability and concurrent validity of the movement assessment battery for children.

Reliability and concurrent validity of the Movement Assessment Battery for Children were evaluated with a sample of 106 boys and girls, distributed into four age groups: 5-6 yr. (n = 20), 7-8 yr. (n = 20), 9-10 yr. (n = 46), and 11-12 yr. (n = 20). Test-retest reliability of the Movement Assessment Battery for Children, estimated using intraclass correlation coefficients, was high across all age groups, and concurrent validity yielded moderate Pearson correlation coefficients between the Move ment battery and long and short forms of the Bruininks-Oseretsky Test of Motor Proficiency. These results support the use of the Movement battery as a measure of motor ability in children, ages 5 to 12 years.     

Effect of color schemes and environmental sensitivity on job satisfaction and perceived performance

Effects of interior office color and individual stimulus screening ability, i.e. instinctive perceptual filtering of irrelevant stimuli, on perceived performance and job satisfaction were examined on various outcome measures over a 4-day work week in a laboratory setting. Workers performed specific tasks and worked regular hours for 4 consecutive days in the same office. They were separated into three groups according to their ability to ignore irrelevant stimuli in the interior space. Those in the white and predominantly blue-green offices reported higher perceived job performance and satisfaction than those in the predominantly red office regardless of stimulus screening ability. Workers with high to moderate stimulus screening ability indicated greater perceived performance and job satisfaction than did workers with low stimulus screening ability. Results for color schemes are discussed in terms of preference and social expectations.     

Diurnal cycle of salivary cortisol in older adult men and women with subjective complaints of memory deficits and/or depressive symptoms: relation to cognitive functioning

In populations of young and older adults, it has been shown that individuals may be categorized into one of three diurnal subgroups when salivary cortisol levels are assessed over a 2-day period and compared for their consistency across days: a typical subgroup, a flat subgroup, and an inconsistent subgroup. Interestingly, recent studies have reported that the typical subgroup represents the majority of the young and older adult population, a finding that is difficult to reconcile with previous studies showing increased cortisol levels in older adults with depression or cognitive impairments. In order to assess whether a typical diurnal cortisol profile is representative across different subgroups of older adults, we assessed diurnal cortisol cycle representation in a sample of older adults with subjective complaints of depression and/or memory problems. Furthermore, given the robust relationship between cortisol and cognitive function, the present study examined the association between the three diurnal subgroups and cognitive performance. Forty-two older individuals were recruited on the basis of reporting subjective complaints of either memory problems and/or depressive mood. Participants were asked to sample their saliva over a 2-day period and were then asked to undergo a neuropsychological evaluation that taps into short-term memory, declarative memory and language. The results showed that 69% of the sample presented a Flat cycle of salivary cortisol over a 2-day period while 19% presented an inconsistent pattern and 12% presented a typical pattern. Participants in the flat subgroup were significantly impaired on letter verbal fluency. Furthermore, a relationship was found between diurnal cortisol subgroup representation and subjective complaint profile. These findings show that older adults with complaints of memory problems and/or depressive symptoms do not present the typical profile of the diurnal cortisol cycle, and they provide a preliminary view of how diurnal cortisol profile relates to cognitive function during human aging.     

An examination of age and cognitive test performance across job complexity and occupational types

In this study, job complexity and occupational type were examined as potential moderators of the relationship between age and cognitive ability. Data included general, verbal, and numerical ability scores for 21,646 individuals in the General Aptitude Test Battery (GATB) data base. These individuals comprised 102 unique samples and 10 major occupational groups. Differences in the relationship between age and cognitive ability test scores were observed across occupational types but not for different levels of job complexity. Findings were discussed in terms of a need for research that examines specific life and work experiences and how such experiences may influence an individual's cognitive abilities across the life span.     

VALIDATING SYNTHETIC VALIDATION: COMPARING TRADITIONAL AND SYNTHETIC VALIDITY COEFFICIENTS

We describe a unique application of a synthetic validation technique to a selection system development project in a large organization. Job analysis data were collected from 4,725 job incumbents and 619 supervisors, and were used to identify 11 job families and 27 job components. We developed 12 tests to predict performance on these job components and conducted a concurrent validation study to collect test and job component data for 1,926 incumbents. We created a test composite for each job component and then chose a test battery for each job family based on its relevant job components. Synthetic validity coefficients were computed for each test battery and compared to traditional validity coefficients that were computed within job families with large sample sizes. The synthetic validity coefficient was very close to the within-family validity coefficient for most job families and was within the bounds of sampling error for all job families. Validities tended to be highest when predictors were weighted according to the number of job components to which they were relevant and job component criterion measures were unit weighted.     

Performance of children with attention deficit hyperactivity disorder (ADHD) on a test battery of impulsiveness.

Children with ADHD were compared to healthy controls on a task battery of cognitive control, measuring motor inhibition (Go/No-Go and Stop tasks), cognitive inhibition (motor Stroop and Switch tasks), sustained attention and time discrimination. Children with ADHD showed an inconsistent and premature response style across all 6 tasks. In addition they showed task-specific impairments in measures of sustained attention, time discrimination, and motor inhibition, but spared cognitive inhibition. Measures of impairment correlated with behavioral hyperactivity and with each other, suggesting that they measure interrelated aspects of a multifaceted construct of cognitive impulsiveness. The task battery as a whole showed 76% correct discrimination of cases and controls.     

Repeated assessment of cognition in children and the measurement of performance change.

There is limited understanding of the problems associated with repeated neuropsychological assessment in children, including the statistics used to guide decisions about cognitive change. This study investigated the utility of a computerized assessment battery that was specifically designed for the repeated assessment of cognitive function in children. Eighty-seven participants aged 8 to 12 years completed the battery four times within a 2-hour testing session. The results support the application of this assessment battery for measuring cognitive change in children. A novel method for calculating measurement error is employed, and its use in the detection of cognitive change in individual children is discussed. An estimate of the measurement error within each of the tests is provided, and recommendations are made regarding the application of this assessment battery for measuring cognitive change in children.     

PROJECT A VALIDITY RESULTS: THE RELATIONSHIP BETWEEN PREDICTOR AND CRITERION DOMAINS

A predictor battery of cognitive ability, perceptual-psychomotor ability, temperament/personality, interest, and job outcome preference measures was administered to enlisted soldiers in nine Army jobs. These measures were summarized in terms of 24 composite scores. The relationships between the predictor composite scores and five components of job performance were analyzed. Scores from the cognitive and perceptual-psychomotor ability tests provided the best prediction of job-specific and general task proficiency, while the temperament/personality composites were the best predictors of giving extra effort, supporting peers, and exhibiting personal discipline. Composite scores derived from the interest inventory were correlated more highly with task proficiency than with demonstrating effort and peer support. In particular, vocational interests were among the best predictors of task proficiency in combat jobs. The results suggest that the Army can improve the prediction of job performance by adding non-cognitive predictors to its present battery of predictor tests.     

Adherence to antiretroviral medications in HIV: differences in data collected via self-report and electronic monitoring.

Controversy remains regarding the reliability of methods used to determine adherence to antiretroviral medication in HIV. In this study the authors compared adherence rates of 119 HIV-positive participants during a 6-month study, as estimated via electronic monitoring (EM) and self-report (SR). Adherence for both short (4-day) and long (4-week, or intervisit) periods was examined, as well as factors that underlie discrepancies between EM and SR. Results showed that intervisit EM estimates were consistently lower than those of SR. SR estimates based on shorter periods (4 days) were closer to those of EM. Higher discrepancies between EM and SR estimates were associated with lower cognitive functioning and externalized locus of control. These findings lend support for using both EM and SR methods; however, study design (e.g., length) and other factors (e.g., cognitive status, cost) should be considered.     

Intensive cognitive behavioural group treatment for social phobia: a pilot study

The aim of this pilot study was to examine the effectiveness of an intensive form of cognitive behavioural group treatment practised routinely in a psychiatric clinic. A total of 27 outpatients with social phobia of long duration were assigned to a 41-hour treatment administered over 2 periods of 3.5 and 4.5 days, 1 week apart. Four groups, each comprising 6-8 patients, participated in the study. All except 1 patient (26/27) completed the treatment and 20 patients participated in all follow-up sessions after 3, 6 and 12 months. Treatment significantly reduced fear and avoidance of social interaction and performance, anticipatory anxiety and symptoms' influence on daily life. Follow-up assessments indicated maintained or increased improvement from post-test to 1 year and large sensitivity to treatment at both post-test and 1 year. Of the patients in the study, 85% were taking a prescribed drug, and 70% had taken medication for at least 1 year before they entered the treatment. At 1-year follow-up 52% had discontinued medication.