Acute Stress Attenuates Cognitive Flexibility in Males Only: An fNIRS Examination

Cognitive processes that afford us the ability to control thoughts and achieve goal-directed behavior are known as executive functions. Empirical evidence in the past few years has demonstrated that executive functions can be influenced by acute stress. The impact of acute stress on cognitive flexibility, a key aspect of executive functions, has received little attention in the literature. We present the results of two experiments conducted to examine the effect of acute stress on cognitive flexibility. Acute stress was induced using the cold pressor task. Cognitive flexibility was assessed using the Wisconsin Card Sorting Test (WCST). Across both experiments acute stress had an attenuating effect on task switching on the WCST. Our findings also indicate that this effect was moderated by the participant’s gender. In Study 1, we observed that following stress exposure male participants in the stress condition made more perseverative errors than participants in the control group. In Study 2, we examined the bilateral hemodynamics in the prefrontal cortex (PFC) during acute stress induction using functional near infrared spectroscopy (fNIRS). Our analysis indicated that functional oxyHb signals fluctuated with greater amplitude than systemic components for participants in the stress group relative to those in the control group. In addition, oxyHb levels post stress induction were correlated with performance on the WCST for the male participants in the stress group only. Concordant with previous reports, our findings indicate that acute stress impacts cognitive flexibility in males and females differentially. Our work also demonstrates the feasibility of using fNIRS as a practical and objective technique for the examination of hemodynamics in the PFC during acute stress.

Latent profiles of executive functioning in healthy young adults: evidence of individual differences in hemispheric asymmetry

Two competing theoretical models of individual differences in executive functioning (EF) were examined: the Prefrontal Convexity Model and the Hemispheric Asymmetry Model. Neurologically healthy individuals (N = 315; mean age 20.8) completed a modified switching task (MST) and the Attention Network Test (ANT) in a single testing session. Data analysis was conducted in two phases. In the first phase (model identification), latent profile analysis was applied to MST variables measuring the abilities to form, switch, and maintain mental sets under conditions designed to tax left or right hemisphere resources. In the second phase (model validation), participant clusters obtained from the first phase were compared on the ANT. The Model Identification phase yielded a 3-profile solution consistent with the Hemispheric Asymmetry Model. Profile 1 (N = 203) was characterized by average EF performances. Profile 2 (N = 43) revealed a set maintenance weakness under non-verbal conditions. Profile 3 (N = 38) demonstrated weaknesses in cognitive flexibility combined with poor executive performances under verbal conditions. The Model Validation phase confirmed group differences. Profile 1 demonstrated average EF performances. Profile 2 demonstrated distractibility and decreased alertness, consistent with a right hemisphere weakness. Profile 3 demonstrated cognitive rigidity in the absence of external cues, consistent with a left hemisphere weakness. Individual differences in EF appear to follow a Hemispheric Asymmetry Model of EF among neurologically healthy adults. Investigating the relationship between hemispherically mediated executive functions and other individual difference factors known to confer health risk or resilience could inform numerous disciplines within the field of psychology.

Executive function in deficit schizophrenia: what do the dimensions of the Wisconsin Card Sorting Test tell us?

Neuropsychological characterization of the schizophrenia deficit syndrome is an unresolved issue. The initial assumption was that patients with deficit syndrome show more definitive impairments on tests sensitive for frontal and parietal functions compared with nondeficit patients,but recent studies failed to confirm this assumption. The fundamental question is whether a more refined delineation of executive dysfunctions is able to yield differences between deficit and nondeficit patients. To investigate this question, we implemented a factor analytic approach to explore potential differences between deficit and nondeficit patients using the Wisconsin Card Sorting Test (WCST). Our paper presents an exploratory factor analysis of the WCST on schizophrenia patients and healthy samples, and a comparison among deficit, non-deficit patients with schizophrenia and control samples using the identified factors. A total of 154 patients with schizophrenia fulfilling the criteria for the deficit syndrome, 121 nondeficit patients, and 130 healthy controls were compared. Factor analysis of the WCST variables using the principal component method resulted in a two-factor solution. Comparison of the diagnostic groups on each of the factors revealed that deficit schizophrenia patients suffer from a more severe degree of impairment on the 'General executive function' factor than nondeficit schizophrenia patients. To our knowledge this is the first study that compared patients with the deficit and non-deficit forms of schizophrenia using WCST factor analytic techniques. Our results provide an insight into the cognitive profile of schizophrenia patients with regard to WCST, which could serve as a framework for future clinical and research endeavors.

Construct Validity of the Wisconsin Card Sorting Test-64 in Patients with Stroke

This study examined the factor structure and contrasted-group validity of the Wisconsin Card Sorting Test-64 (WCST-64) in a stroke sample (n = 112). Confirmatory factor analyses were used to compare five different models suggested by prior factor analyses. The results indicated that the WCST-64 was best represented by a three-dimensional model comprising response inflexibility (factor 1), ineffective hypothesis-testing strategy (factor 2), and set maintenance (factor 3). A significant overall multivariate effect for group (F = 2.87, df = 18,495.46, p <.001) was found in a multivariate analysis of covariance with WCST scores as dependent variables and four different groups (three stroke subgroups with different levels of cognitive function and a normal control group) as independent variable, after controlling for gender. The results of discriminant analysis supported the use of the WCST-64 in stroke patients with cognitive impairment.

Treating adolescents with social anxiety disorder in school: an attention control trial

BACKGROUND

Anxiety disorders are often undetected and untreated in adolescents. This study evaluates the relative efficacy of a school-based, cognitive-behavioral intervention compared to an educational-supportive treatment for adolescents with social anxiety disorder.

METHODS

Thirty-six students (30 females), ages 14 to 16, were randomized to a 12-week specific intervention, Skills for Social and Academic Success (SASS), or a credible attention control matched for structure and contact, conducted in school.

RESULTS

Independent evaluations and adolescent self-reports indicated significant reduction in social anxiety for SASS compared to the control group. Parent reports of their children's social anxiety did not discriminate between treatments. In the specific intervention, 59%, compared to 0% in the control, no longer met criteria for social anxiety disorder following treatment. Superiority of the SASS intervention was maintained 6 months after treatment cessation.

CONCLUSIONS

The study provides evidence that intervention for social anxiety disorder that emphasizes exposure and social skills is efficacious. Results indicate that clinical improvement is sustained for at least 6 months, and that, overall, adolescents with social anxiety disorder do not respond to non-specific treatment. This investigation has public health implications by demonstrating that effective interventions can be transported to nonclinical settings.

The frontal hypothesis of cognitive aging: factor structure and age effects on four frontal tests among healthy individuals

With 101 healthy aging adult participants, the authors investigated whether executive functions are a unitary concept. The authors established the factor structure of the Wisconsin Card Sorting Test (WCST; E. A. Berg, 1948), the Stroop color and word test (C. J. Golden, 1978), verbal fluency using the Controlled Oral Word Association Test (COWAT; Benton, 1967), and the Digits Backwards subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R; D. Wechsler, 1981). The authors also evaluated the extent to which age and other demographic variables predicted common underlying properties of these frontal tests. Results revealed an age-related decline in executive abilities differentially reflected by the selected tasks. These data suggest caution using the COWAT to evaluate executive abilities in older people. The authors interpret findings to support the unitary view of executive abilities and the executive decline proposed by the frontal hypothesis.

School-Based Intervention for Adolescents with Social Anxiety Disorder: Results of a Controlled Study

Social anxiety disorder, whose onset peaks in adolescence, is associated with significant impairment. Despite the availability of effective treatments, few affected youth receive services. Transporting interventions into schools may circumvent barriers to treatment. The efficacy of a school-based intervention for social anxiety disorder was examined in a randomized wait-list control trial of 35 adolescents (26 females). Independent evaluators, blind to treatment condition, evaluated participants at preintervention, postintervention, and 9 months later. Adolescents in the intervention group demonstrated significantly greater reductions than controls in social anxiety and avoidance, as well as significantly improved overall functioning. In addition, 67% of treated subjects, compared to 6% of wait-list participants, no longer met criteria for social phobia following treatment. Findings support the possible efficacy of school-based intervention for facilitating access to treatment for socially anxious adolescents.

Confirmatory factor analysis of the behavioral dyscontrol scale in a mixed clinical sample

The Behavioral Dyscontrol Scale (BDS) is a brief measure of executive functioning originally designed for use primarily with older adults. Previous research suggests that factors derived from exploratory factor analysis of the BDS have clinical utility and are theoretically meaningful; however, the factor structure has not been previously submitted to confirmatory analysis, and there are several potential methodological problems with the previous exploratory factor analysis. In this study, we conducted a confirmatory factor analysis of the BDS. Findings were largely consistent with the original exploratory analysis (Grigsby, Kaye, & Robbins, 1992) in suggesting a three-factor model, although the three-factor model was a better fit if factors were allowed to correlate with one another. The findings of this study lend support to the current practice of using factor scores in clinical and research applications.

Factor structure of nonverbal cognition

In order to define the factor structure of nonverbal cognitive processes, 156 twenty to sixty year-old participants were selected in Medellin (Colombia). A neuropsychological test battery for assessing different nonverbal cognitive domains (attention, memory, visuoperceptual and visuoconstructive abilities. executive functions, praxis abilities, and written calculation abilities) was administered. Initially, independent factor analyses were carried out for each domain. Three attention factors (Sustained Attention, Divided Attention, and Processing Speed, 73.1% of the variance); two memory factors (Categorical and Non-Categorical Memory, 59.7% of the variance): two visuoperceptual and visuoconstructive factors (Sequential and Simultaneous, 54.0% of the variance); and two executive function factors (Categorization and Trial Error, 82.0% of the variance) were found. Further, several sequential factor analyses using Varimax orthogonal rotations for noncorrelated variables were performed. The 32 test variables were included, but progressively some variables were removed. This procedure finally selected 13 variables corresponding to five factors accounting for 72.6% of variance. Factor I was an Executive Function factor (30% of variance). Factor 2 corresponded to a Sequential Constructional factor (14.7%). Factor 3 represented a Processing Speed factor and accounted for 10.6% of the variance. Factor 4 was Visuoperceptual factor (9.5% of the variance). Finally, Factor 5 (7.8% of the variance) was a Nonverbal Memory factor. It was concluded that several, different cognitive dimensions are included in nonverbal cognition.

Performance on the Wisconsin Card Sorting Test after traumatic brain injury

The performance of 100 patients with traumatic brain injury (TBI) on the Wisconsin Card Sorting Test (WCST) was examined to determine the underlying latent structure as well as profile subtypes. Exploratory factor analysis with oblique rotation identified three factors: response accuracy, learning, and failure to maintain set. Marker variables from each factor were then included in a two-stage cluster analysis, which identified two reliable subtypes. Level of performance differences between these subtypes were meaningfully related to both demographic background and length of coma. It is concluded that interpretation of the WCST results of patients with TBI should consider the multifactorial nature of the instrument in combination with injury severity characteristics and demographic variables.