Influence of regular aerobic exercise on psychological health: a randomized, controlled trial of healthy middle-aged adults

Although a variety of psychological benefits have been attributed to regular exercise, few experimentally controlled studies of healthy individuals currently exist. One hundred twenty healthy, sedentary, middle-aged men and women were randomly assigned to either a 6-month home-based aerobic exercise training program or to an assessment-only control condition. Adherence across the 6-month period was found by both self-report and heart rate microprocessor methods to exceed 75% in both sexes. To assess changes in a variety of psychological variables over time, a 14-item Likert rating scale was completed and returned on a biweekly basis throughout the 6-month period. Slope analyses conducted on the 11 items attaining acceptable test-retest reliability coefficients showed significant between-groups differences on the 3 items most closely associated with the actual physical changes that occurred with exercise (all ps less than .004). Implications in relation to repeated measurement of psychological changes in nonclinical populations and the determination of the relevant population-, activity-, and program-specific parameters involved are discussed.     

Effects of consistent aerobic exercise on the psychological functioning of women

Effects of consistent aerobic exercise on depression, anxiety, and health locus of control for a group of nonclinical inactive women were investigated. Type A and Type H (hard-driving) behavioral styles were evaluated to determine whether these traits were related to exercise improvement. 26 women were randomly assigned to either an exercise group (n = 10) or exercise with cognitive strategy instructions (n = 16). All subjects increased distance run in 12-min. run test from pre- to posttest. Women improved in depression and trait anxiety. Depression was significantly correlated with body mass index at end of program. Posttest state-anxiety was significantly correlated with 6-wk. follow-up of exercise frequency. No significant difference in pre- and posttest health locus of control was found. Type H scores were significantly correlated with number of exercise sessions attended. Consistent aerobic exercise had a positive effect on psychological functioning, and some characteristics may affect exercise improvement.     

Mood state changes of women as a function of regular aerobic exercise

The present study examined mood states of aerobic exercisers before and after completing a 15-wk. program. The subjects (ages 18 to 36 yr.) were 86 women enrolled in activity classes at a large state school in the southeast. Subjects were initially classified according to previous exercise habits. Analysis indicated both groups of frequent and infrequent exercisers were similar in mood states. Participation in regular exercise did not significantly change or enhance the mood states from pretreatment measures. Pretest measures of mood states provided poor prediction of posttest measures, indicating extreme variability in subjects' scores.     

Benefits of physical exercise on executive functions in older people with Parkinson’s disease

The benefits of physical exercise on cognitive functioning have been reported in the literature, but the potential benefits to slow the eventual decline in executive functioning (EF) caused by neurodegeneration from Parkinson’s Disease (PD) have rarely been studied. Thus the objective of this study was to analyze the effects of a multimodal physical exercise program on EF in older people with Parkinson’s disease. The EF of the older people was evaluated by neuropsychological testing, and for confounding variables such as attention, depressive symptoms and anxiety, before and after intervention. The 20 participants were assigned into Control (CG) and Trained (TG) Groups. The TG participated in generalized physical training for 6 months. The ANOVA showed a significant interaction (p < .05) that indicated a beneficial contribution of training on EF. No significant interactions were found in the results for confounding variables between groups and pre- and post-intervention, which supports the beneficial findings of physical exercise training on EF.     

Parent-reported executive functioning in young children treated for cancer

It is well known that children treated for cancer are at risk for cognitive and functional impairments. Such research is largely based on studies of late effects in school-aged or older children. However, far less is known about executive function weaknesses in preschool-aged children treated for cancer. Thus, the aim of this study was to examine executive functioning in a clinically referred sample of young oncology patients, and its association with broader domains of functioning. Data from 61 young children with cancer, who were referred for clinical cognitive evaluations, were abstracted and included in this study. Patients were 5.00 years of age (SD = 0.72) at assessment, 54.1% male, and two-thirds (63.9%) had been treated for brain tumors. Most executive functions were significantly discrepant from the mean, with 47.5% of preschoolers having parent-reported working memory concerns within the clinically significant range. There were no differences in executive functioning based on diagnosis or treatment status. Parent-reported executive functioning was strongly correlated with global intelligence and adaptive functioning, with some indices also associated with nonverbal problem solving and pre-academic skills. Ultimately, results indicate the presence of emerging weaknesses in executive functioning in young children with cancer, and add to a growing body of literature highlighting the potential cognitive and behavioral risks associated with a cancer diagnosis in early childhood.     

Intergenerational transmission of neuropsychological executive functioning

Relationships between parent and child executive functioning were examined, controlling for the critical potential confound of IQ, in a family study involving 434 children (130 girls and 304 boys) and 376 parents from 204 community recruited families at high risk for the development of substance use disorder. Structural equation modeling found evidence of separate executive functioning and intelligence (IQ) latent variables. Mother’s and father’s executive functioning were associated with child’s executive functioning (beta = 0.34 for father–child and 0.51 for mother–child), independently of parental IQ, which as expected was associated with child’s IQ (beta = 0.52 for father–child and 0.54 for mother–child). Familial correlations also showed a significant relationship of executive functioning between parents and offspring. These findings clarify that key elements of the executive functioning construct are reliably differentiable from IQ, and are transmitted in families. This work supports the utility of the construct of executive function in further study of the mechanisms and etiology of externalizing psychopathologies.     

Understanding the executive functioning heterogeneity in schizophrenia

Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia patients. Furthermore, it is still unknown if the executive impairments observed in schizophrenia are better characterized as specific or as reflecting generalized cognitive factors. The four executive processes (i.e. updating, inhibition, shifting and divided attention) described in Miyake et al.'s (2000) theoretical model were examined in 62 individuals with schizophrenia and 49 healthy controls. At group level, impairments in all four executive processes confirmed the marked impairment in executive functioning in patients with schizophrenia. Statistical analysis indicated that executive performances in schizophrenia patients were more heterogeneous than in healthy controls. Compared with standardized norms, 94% of patients exhibited impairment in at least one of the executive tasks. Twenty-one percent of patients exhibited impairment in one executive task, 27% in two tasks, 23% in three executive tasks and 23% exhibited impairments in the four executive tasks. Six percent of patients had normal executive profile. Regression analysis indicated that only premorbid intellectual quotient and a general slowing in processing speed predicted the executive dysfunction severity. Executive functioning was not affected by age, duration of illness, psychotic status, or by antipsychotic dosage. Our results emphasize the heterogeneity of the dysexecutive syndrome in schizophrenia when individual profile analysis is considered, and extend the view that individual cognitive differences in schizophrenia are largely underlined by general cognitive factors such as intellectual level and general processing speed.     

Acute aerobic exercise and information processing: Modulation of executive control in a Random Number Generation task

The immediate and short-term aftereffects of a bout of aerobic exercise on young adults’ executive functions were assessed. Sixteen participants performed a Random Number Generation (RNG) task, which measured two aspects of executive function, before, during, and after ergometer cycling exercise. In a separate session, participants completed the same sequence of testing while seated on an ergometer without pedaling. Results suggest that aerobic exercise: (1) selectively influences RNG indices related to the ability to alternate ascending and descending runs throughout the entire exercise bout; (2) induces a shift to a less effortful number generation strategy, particularly during the first few minutes of the exercise; and (3) has no significant influence on RNG performance as soon as the exercise terminates. The strategic adjustments observed during the exercise are interpreted in the framework of Hockey’s [Hockey, G. R. J. (1997). Compensatory control in the regulation of human performance under stress and high workload: A cognitive-energetical framework. Biological Psychology, 45, 73-93.] compensatory control model and suggest that concurrent effortful processes induced by cycling exercise may draw upon available attention resources and influence executive processing.     

Development of executive functioning in school-age Tunisian children

Research regarding executive functioning (EF) in children rarely focuses on populations in African or Middle-Eastern Arabic-speaking countries. The current study used a cross-sectional design to examine the developmental trajectories of school-age Tunisian children in three domains of executive control (inhibition of prepotent responses, cognitive flexibility, and working memory) as well as their mutual interactions and the effects of gender and parents’ education level. Inhibitory processes, cognitive flexibility, and working memory were assessed using the Stroop test, a version of the Hayling test adapted for children, simple and alternating tasks of verbal fluency, and verbal and visuospatial span tasks (forward and backward spans). The study population included 120 7- to 12-year-old Tunisian children (60 girls, 60 boys) who were grouped and matched for age, gender, and parents’ education level. The results revealed an overall effect of age on executive performance, whereas gender and parents’ education level showed non-significant effects. In addition, executive indices were significantly associated with fluid intelligence level. Partial correlation analyses (controlled for age) found significant links between indices that assessed the same executive process, except for inhibitory processes; the temporal indices for inhibitory processes showed relative independence. The correlations between indices that assessed distinct executive processes were weaker (but significant). Overall, the results suggest that executive components in school-age Tunisian children operate according to relatively homogeneous developmental trajectories, marked by peaks of maturity that differ according to the assessed index. A transcultural approach to EF is discussed in terms of the unity and diversity of its components.     

Bilingual experience and executive functioning in young children

Advanced inhibitory control skills have been found in bilingual speakers as compared to monolingual controls (Bialystok, 1999). We examined whether this effect is generalized to an unstudied language group (Spanish-English bilingual) and multiple measures of executive function by administering a battery of tasks to 50 kindergarten children drawn from three language groups: native bilinguals, monolinguals (English), and English speakers enrolled in second-language immersion kindergarten. Despite having significantly lower verbal scores and parent education/income level, Spanish-English bilingual children's raw scores did not differ from their peers. After statistically controlling for these factors and age, native bilingual children performed significantly better on the executive function battery than both other groups. Importantly, the relative advantage was significant for tasks that appear to call for managing conflicting attentional demands (Conflict tasks); there was no advantage on impulse-control (Delay tasks). These results advance our understanding of both the generalizability and specificity of the compensatory effects of bilingual experience for children's cognitive development.     

Dimensions of executive functioning: Evidence from children

This study investigated dimensions of executive functioning in 8‐ to 13‐year‐old children. Three tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB), two tasks from the NEPSY battery and some additional executive function (EF) tests were administered to 108 children. In line with earlier work, modest correlations among EF measures were obtained (r < .4). Both exploratory and confirmatory factor analyses yielded three interrelated factors, which resembled those obtained by Miyake et al. (2000) and which were—with some reservations—labelled Working Memory (WM), Inhibition and Shifting. Age correlated with performance on most individual EF measures as well as Shifting and WM. The present findings are in agreement with contemporary views as to the simultaneous unity and diversity of EFs.     

The effects of bilingualism on toddlers' executive functioning

Bilingual children have been shown to outperform monolingual children on tasks measuring executive functioning skills. This advantage is usually attributed to bilinguals’ extensive practice in exercising selective attention and cognitive flexibility during language use because both languages are active when one of them is being used. We examined whether this advantage is observed in 24-month-olds who have had much less experience in language production. A battery of executive functioning tasks and the cognitive scale of the Bayley test were administered to 63 monolingual and bilingual children. Native bilingual children performed significantly better than monolingual children on the Stroop task, with no difference between groups on the other tasks, confirming the specificity of bilingual effects to conflict tasks reported in older children. These results demonstrate that bilingual advantages in executive control emerge at an age not previously shown.     

Personality and executive functioning as risk factors in recidivists

The classification of an inmate population at a maximum security jail in Canada was undertaken to study factors correlated with recidivism. A total of 12 recidivists and 12 nonrecidivists were classified according to their index offenses, and a Criminal Record search was completed to verify their statements. A total of 15 non-offenders who had also undergone a criminal record check were included as controls. All participants were administered the Minnesota Multiphasic Personality Inventory-168, Violence Risk Scale-Experimental Version, Coopersmith Self-esteem Inventory, and the Wisconsin Card Sorting Task. Statistical analysis showed significant differences between the groups on scores for the Hypochondriasis, Psychopathic Deviate, and Hypomania scales of the MMPI-168. Significant differences were noted for the Wisconsin Card Sorting Task and the Violence Risk Scale. Discriminant analysis of the recidivists and nonrecidivists correctly classified at a 91.3% level.     

Time monitoring and executive functioning in children and adults

This study examined time-based prospective memory performance in relation to individual and developmental differences in executive functioning. School-age children and young adults completed six experimental tasks that tapped three basic components of executive functioning: inhibition, updating, and mental shifting. Monitoring performance was examined in a time-based prospective memory task in which participants indicated the passing of time every 5min while watching a movie. Separate analyses of the executive functioning data yielded a two-factor solution for both age groups, with the updating and inhibition tasks constituting a common factor and the shifting tasks constituting a separate factor. Both children and adults showed accelerating monitoring functions with low rates of clock checking during the early phase of each 5-min interval. However, compared with adults, children needed more clock checks for obtaining the same level of response accuracy. Executive functioning had selective effects on time-based prospective memory performance. In both children and adults, monitoring performance was related to the inhibition and updating components, but not to the shifting component, of executive functioning. We conclude that difficulties in temporary maintenance and updating of working memory contents may create discontinuities in sense of time, leading to an increased reliance on external cues for time keeping.     

Updating information in verbal working memory and executive functioning

50 older adults (M age=77.9 yr., SD=7.3; 35 women and 15 men) were tested using the updating working-memory task. They were also given the neuropsychological Wisconsin Card Sorting Test, assumed to evaluate executive functioning and the frontal cortex. A factor analysis with age, education, and verbal ability partialled out was computed on the updating task outcomes and resulted in a two-factor solution, indicating that this task requires two independent processes, interpreted as reflecting a storage component and an updating component. Partial correlations with age, education, and verbal ability partialled out indicated that Wisconsin Card Sorting Test measures were significantly associated with the factor supposed to reflect the updating process. Such results appeared consistent with the model of working memory with a central executive system involved in the updating process and related to the executive-frontal functioning, and a phonological loop system involved in the storage of verbal information and not linked to executive-frontal functions.     

The role of the executive system in visuo-spatial memory functioning

Participants were presented with a spatial sequence in which between 4 and 10 cells were highlighted. On each trial list length was unknown to the participant who was required to serially recall the last four cells. Processing of longer lists is assumed to call upon the executive system, which is thought to be involved in updating the contents of the short-term visuo-spatial store. Study 1 revealed that loading the executive system with concurrent random letter generation impaired performance on the spatial task especially recall of the early serial positions. However, contrary to expectation the degree of impairment was no greater on the longer lists, where it had been assumed that updating would be occurring. Study 2 confirmed this finding and demonstrated that relative to sequences of known length, under conditions of uncertainty when the list length was unknown, spatial recall was impaired even on short sequences. The present results support the growing consensus, which is suggestive of closer links between visuo-spatial and executive processes. However, it remains unclear whether or not updating is actually occurring on the longer sequences, and if it is, what specific executive processes are involved.