Assessing the Concurrent Validity of a Novel Performance-Based Task of Executive Functioning

Research has found that performance-based tests of executive functioning (PBT-EF) have inherent characteristics that limit their use in describing functioning in an ecologically valid manner. Recommendations have been made to improve prediction of everyday functioning, and the Functional Assessment of Verbal Reasoning and Executive Strategies (FAVRES) appeared promising. The current study investigated the concurrent validity of the FAVRES. It was hypothesized that the FAVRES would be a better predictor of everyday EF than an estimate of intelligence and, true to its goal, other PFT-EF. University undergraduate students and community members were invited to participate in the study. Participants (N = 78; 63% Female, Mage = 22 years) completed a demographic questionnaire, as well as the FAVRES, the Wechsler Test of Adult Reading (WTAR; an estimate of intelligence) and the Behavior Rating Inventory of Executive Function - Adult (BRIEF-A; a self-report measure of everyday EF). FAVRES and WTAR scores were used in a hierarchical regression model to predict BRIEF-A scores. Neither FAVRES nor WTAR scores predicted BRIEF-A scores. Post-hoc analyses revealed a relation between FAVRES performance and WTAR scores; whereas BRIEF-A scores were predicted by participant History of Psychopathology and State Distress. These findings indicate a stronger relation between psychopathology and everyday EF than between intelligence or PBT and everyday EF. Future investigation into the effect of emotion on EF related behaviours may be one avenue to improved performance-based measurement of EF

A problem-solving task specialized for functional neuroimaging: Validation of the Scarborough adaptation of the Tower of London (S-TOL) using near-infrared spectroscopy

Problem-solving is an executive function subserved by a network of neural structures of which the dorsolateral prefrontal cortex (DLPFC) is central. Whereas several studies have evaluated the role of the DLPFC in problem-solving, few standardized tasks have been developed specifically for use with functional neuroimaging. The current study adapted a measure with established validity for the assessment of problem-solving abilities to design a test more suitable for functional neuroimaging protocols. The Scarborough adaptation of the Tower of London (S-TOL) was administered to 38 healthy adults while hemodynamic oxygenation of the PFC was measured using 16-channel continuous-wave functional near-infrared spectroscopy (fNIRS). Compared to a baseline condition, problems that required two or three steps to achieve a goal configuration were associated with higher activation in the left DLPFC and deactivation in the medial PFC. Individuals scoring higher in trait deliberation showed consistently higher activation in the left DLPFC regardless of task difficulty, whereas individuals lower in this trait displayed less activation when solving simple problems. Based on these results, the S-TOL may serve as a standardized task to evaluate problem-solving abilities in functional neuroimaging studies

Linking trait-based phenotypes to prefrontal cortex activation during inhibitory control

Inhibitory control is subserved in part by discrete regions of the prefrontal cortex whose functionality may be altered according to specific trait-based phenotypes. Using a unified model of normal range personality traits, we examined activation within lateral and medial aspects of the prefrontal cortex during a manual go/no-go task. Evoked hemodynamic oxygenation within the prefrontal cortex was measured in 106 adults using a 16-channel continuous-wave functional near-infrared spectroscopy system. Within lateral regions of the prefrontal cortex, greater activation was associated with higher trait levels of extraversion, agreeableness and conscientiousness, and lower neuroticism. Higher agreeableness was also related to more activation in the medial prefrontal cortex during inhibitory control. These results suggest that personality traits reflecting greater emotional stability, extraversion, agreeableness and conscientiousness may be associated with more efficient recruitment of control processes subserved by lateral regions of the prefrontal cortex. These findings highlight key links between trait-based phenotypes and neural activation patterns in the prefrontal cortex underlying inhibitory control