Verbal fluency, trail making, and Wisconsin Card Sorting Test performance following right frontal lobe tumor resection

Characterizing phonemic fluency by transfer learning with deep language models

Though phonemic fluency tasks are traditionally indexed by the number of correct responses, the underlying disorder may shape the specific choice of words-both correct and erroneous. We report the first comprehensive qualitative analysis of incorrect and correct words generated on the phonemic ('S') fluency test, in a large sample of patients (n = 239) with focal, unilateral frontal or posterior lesions and healthy controls (n = 136). We conducted detailed qualitative analyses of the single words generated in the phonemic fluency task using categorical descriptions for different types of errors, low-frequency words and clustering/switching. We further analysed patients' and healthy controls' entire sequences of words by employing stochastic block modelling of Generative Pretrained Transformer 3-based deep language representations. We conducted predictive modelling to investigate whether deep language representations of word sequences improved the accuracy of detecting the presence of frontal lesions using the phonemic fluency test. Our qualitative analyses of the single words generated revealed several novel findings. For the different types of errors analysed, we found a non-lateralized frontal effect for profanities, left frontal effects for proper nouns and permutations and a left posterior effect for perseverations. For correct words, we found a left frontal effect for low-frequency words. Our novel large language model-based approach found five distinct communities whose varied word selection patterns reflected characteristic demographic and clinical features. Predictive modelling showed that a model based on Generative Pretrained Transformer 3-derived word sequence representations predicted the presence of frontal lesions with greater fidelity than models of native features. Our study reveals a characteristic pattern of phonemic fluency responses produced by patients with frontal lesions. These findings demonstrate the significant inferential and diagnostic value of characterizing qualitative features of phonemic fluency performance with large language models and stochastic block modelling.

Schizophrenia decreases guilt and increases self-disgust: Potential role of altered executive function

Our knowledge of how the more complex self-conscious emotions (SCEs) are affected in schizophrenia is sparse. SCEs, unlike basic emotions, involve sophisticated frontal-lobe-related cognition, impairment of which characterizes the neurocognitive profile of schizophrenia. We investigated, in a cross-sectional study, whether SCEs (shame, guilt and self-disgust) are affected in schizophrenia, and the relationship between changes in SCEs and executive (dys)function. Twenty-nine Greek and thirty Arabic patients with schizophrenia were recruited alongside twenty-two Greek and thirty Arabic matched controls. Participants were administered the Self-Disgust Scale (TOSCA for shame and guilt was also administered to the Greek sample), and the Trail Making and Verbal Fluency Tests to measure executive function (EF). Trait levels of self-disgust and guilt were found to be higher and lower, respectively, in patients with schizophrenia relative to control participants; and poorer EF was related with higher trait levels of SD, but lower trait levels of guilt. The pattern of findings was largely unaffected when controlling for anxiety and depression. Given that altered levels of SCEs are closely related to poorer EF, we suggest that the link between EF and emotion regulation, widely established in basic emotions but under-studied in SCEs, may explain the current findings.

The Effect of Self-Paced Exercise Intensity and Cardiorespiratory Fitness on Frontal Grey Matter Volume in Cognitively Normal Older Adults: A Randomised Controlled Trial

OBJECTIVE

Exercise has been found to be important in maintaining neurocognitive health. However, the effect of exercise intensity level remains relatively underexplored. Thus, to test the hypothesis that self-paced high-intensity exercise and cardiorespiratory fitness (peak aerobic capacity; VO_2peak) increase grey matter (GM) volume, we examined the effect of a 6-month exercise intervention on frontal lobe GM regions that support the executive functions in older adults.

METHODS

Ninety-eight cognitively normal participants (age = 69.06 ± 5.2 years; n = 54 female) were randomised into either a self-paced high- or moderate-intensity cycle-based exercise intervention group, or a no-intervention control group. Participants underwent magnetic resonance imaging and fitness assessment pre-intervention, immediately post-intervention, and 12-months post-intervention.

RESULTS

The intervention was found to increase fitness in the exercise groups, as compared with the control group (F = 9.88, p = <0.001). Changes in pre-to-post-intervention fitness were associated with increased volume in the right frontal lobe (β = 0.29, p = 0.036, r = 0.27), right supplementary motor area (β = 0.30, p = 0.031, r = 0.29), and both right (β = 0.32, p = 0.034, r = 0.30) and left gyrus rectus (β = 0.30, p = 0.037, r = 0.29) for intervention, but not control participants. No differences in volume were observed across groups.

CONCLUSIONS

At an aggregate level, six months of self-paced high- or moderate-intensity exercise did not increase frontal GM volume. However, experimentally-induced changes in individual cardiorespiratory fitness was positively associated with frontal GM volume in our sample of older adults. These results provide evidence of individual variability in exercise-induced fitness on brain structure.

Multi-model mapping of phonemic fluency

The voluntary generation of non-overlearned responses is usually assessed with phonemic fluency. Like most frontal tasks, it draws upon different complex processes and systems whose precise nature is still incompletely understood. Many claimed aspects regarding the pattern of phonemic fluency performance and its underlying anatomy remain controversial. Major limitations of past investigations include small sample size, scant analysis of phonemic output and methodologically insufficient lesion analysis approaches. We investigated a large number of patients with focal unilateral right or left frontal (n = 110) or posterior (n = 100) or subcortical (n = 65) lesions imaged with magnetic resonance or computed tomography and compared their performance on the number of overall responses, words produced over time, extremely infrequent/unknown words and inappropriate words generated. We also employed, for the first time parcel-based lesion-symptom mapping, tract-wise statistical analysis as well as Bayesian multi-variate analysis based on meta-analytically defined functional region of interest, including their interactions. We found that left frontal damage was associated with greater impairment than right frontal or posterior damage on overall fluency performance, suggesting that phonemic fluency shows specificity to frontal lesions. We also found that subcorticals, similar to frontals, performed significantly worse than posteriors on overall performance suggesting that subcortical regions are also involved. However, only frontal effects were found for words produced over time, extremely infrequent/unknown and inappropriate words. Parcel-based lesion-symptom mapping analysis found that worse fluency performance was associated with damage to the posterior segment of the left frontal middle and superior gyrus, the left dorsal anterior cingulate gyrus and caudate nucleus. Tract-wise statistical analysis revealed that disconnections of left frontal tracts are critical. Bayesian multi-variate models of lesions and disconnectome maps implicated left middle and inferior frontal and left dorsomedial frontal regions. Our study suggests that a set of well localized left frontal areas together with subcortical regions and several left frontal tracts are critical for word generation. We speculate that a left lateralized network exists. It involves medial, frontal regions supporting the process of 'energization', which sustains activation for the duration of the task and middle and inferior frontal regions concerned with 'selection', required due to the competition produced by associated stored words, respectively. The methodology adopted represents a promising and empirically robust approach in furthering our understanding of the neurocognitive architecture underpinning executive processes.

Impaired attention in patients with adrenal insufficiency - Impact of unphysiological therapy

Patients with adrenal insufficiency (AI) are treated with glucocorticoid (GC) replacement therapy. Although current GC regimens aim to mimic the physiological circadian rhythm of cortisol secretion, temporary phases of hypo- and hypercortisolism are common undesired effects. Both conditions may lead to impairment in cognitive functioning. At present, little is known about cognitive functioning in patients with AI, especially regarding the effects of dosage and duration of glucocorticoid replacement therapy. There is also little data available comparing the effects of GC therapy on patients with primary (PAI) and secondary (SAI) forms of AI. In this study 40 adults with AI (21 PAI, 19 SAI) substituted with hydrocortisone (HC) and 20 matched healthy controls underwent 10 different neuropsychological tests evaluating memory, executive functioning, attention, psychomotricity and general intellectual ability. Furthermore demographic data, dosage of HC, duration of therapy and co-medication were evaluated. Patients were compared in groups with regard to diagnosis, dosage and duration of therapy. Patients showed worse performance than controls in attention, though patients with PAI and SAI seemed to be equally impaired. There were no limitations in intellectual abilities or memory function. High dosage of HC was found to impair attention, visual-motoric skills and executive functioning while the duration of therapy showed no significant impact on cognitive functions. In conclusion, our study showed that AI patients on HC replacement therapy reveal significant cognitive deficits concerning attention. There was no difference between patients with PAI and SAI. Furthermore, high dosage seems to have a negative impact especially on executive functioning.

Neural and behavioral correlates of episodic memory are associated with temporal discounting in older adults

When facing decisions involving trade-offs between smaller, sooner and larger, delayed rewards, people tend to discount the value of future rewards. There are substantial individual differences in this tendency toward temporal discounting, however. One neurocognitive system that may underlie these individual differences is episodic memory, given the overlap in the neural circuitry involved in imagining the future and remembering the past. Here we tested this hypothesis in older adults, including both those that were cognitively normal and those with amnestic mild cognitive impairment (MCI). We found that performance on neuropsychological measures of episodic memory retrieval was associated with temporal discounting, such that people with better memory discounted delayed rewards less. This relationship was specific to episodic memory and temporal discounting, since executive function (another cognitive ability) was unrelated to temporal discounting, and episodic memory was unrelated to risk tolerance (another decision-making preference). We also examined cortical thickness and volume in medial temporal lobe regions critical for episodic memory. Entorhinal cortical thickness was associated with reduced temporal discounting, with episodic memory performance partially mediating this association. The inclusion of MCI participants was critical to revealing these associations between episodic memory and entorhinal cortical thickness and temporal discounting. These effects were larger in the MCI group, reduced after controlling for MCI status, and statistically significant only when including MCI participants in analyses. Overall, these findings suggest that individual differences in temporal discounting are driven by episodic memory function, and that a decline in medial temporal lobe structural integrity may impact temporal discounting.

Assessing Discrepancies in Neurocognitive and Patient-Reported Measures of Brain Tumor Survivors

OBJECTIVES

To examine the association between performance-based neurocognitive and patient-reported cognitive function tests and identify characteristics that may explain observed discrepancies as a means to advance intervention development.

SAMPLE & SETTING

40 adults diagnosed with a primary brain tumor (PBT) (high-grade, n = 35) were recruited from two academic neuro-oncology clinics in North Carolina.

METHODS & VARIABLES

Eligibility included a Mini-Mental State Examination score of 24 or greater, having completed cancer treatment, and having tumor stability. Participants completed performance-based neurocognitive and patient-reported cognitive function, demographic, and symptom assessment tests at one time point.

RESULTS

Neurocognitive impairments included executive control, memory, and attention. Age, time since diagnosis, and tumor- or treatment-specific variables were not associated with neurocognitive or patient-reported cognitive function. Those reporting worse cognitive impairment tended also to report greater severity of PBT-specific and depressive symptoms.

IMPLICATIONS FOR NURSING

Patient-reported cognitive concerns warrant additional assessment for potential interventions to maintain function.

Validity of the Verbal Concept Attainment Test in multiple sclerosis

OBJECTIVE

As many as 70% of people with multiple sclerosis (MS) have clinically significant cognitive impairment, and most of these individuals exhibit executive dysfunction. Most research concerning executive dysfunction in MS has focused upon nonverbal measures. The Verbal Concept Attainment Test (VCAT) has demonstrated construct validity as an executive function measure in people infected with HIV and in people with focal brain lesions, but its validity among people with MS is unknown. The current study evaluated the VCAT's criterion, diagnostic, and ecological validity in people with MS.

METHOD

A comprehensive neuropsychological battery was administered to 44 healthy individuals and 97 people with MS. Based on existing norms, they were classified as impaired or unimpaired, resulting in 65 people with MS categorized as unimpaired and 32 as impaired. They were administered a battery assessing neuropsychological impairment and disability status.

RESULTS

The VCAT correlated with most measures of neuropsychological function, but its largest correlations occurred with measures of executive function, working memory, and verbal memory. Regarding classification accuracy, the VCAT achieved satisfactory sensitivity and specificity in identifying neuropsychological impairment in people with MS. The VCAT achieved moderate correlations with measures of disability status.

CONCLUSIONS

The data provide evidence for an optimal VCAT cutoff score for establishing neuropsychological impairment in people with MS, and they demonstrate that the VCAT possesses acceptable criterion, diagnostic, and ecological validity. As such, these data support the inclusion of the VCAT in research and clinical practice involving people with MS.

The bridge between cognition and behavior in acquired brain injury: A graph theoretical approach

BACKGROUND

The assumption is that executive dysfunctions (EF), associated with frontal lobe injury, are responsible for behavioral disturbances. Some studies do not find a relationship between EF and behavior following frontal lobe lesions. Our main goal of this study was to use a novel statistical method, graph theory, to analyze this relationship in different brain injury groups; frontal lobe damage, non-frontal lobe damage, and controls. Within the frontal group, we expect to find a pattern of executive nodes that are highly interconnected.

METHODS

For each group, we modeled the relationship between executive functions and behavior as a network of interdependent variables. The cognitive tests and the behavioral questionnaire are the "nodes" in the network, while the relationships between the nodes were modeled as the correlations between two nodes corrected for the correlation with all other nodes in the network. Sparse networks were estimated within each group using graphical LASSO. We analyzed the relative importance of the nodes within a network (centrality) and the clustering (modularity) of the different nodes.

RESULTS

Network analysis showed distinct patterns of relationships between EF and behavior in the three subgroups. The performance on the verbal learning test is the most central node in all the networks. In the frontal group, verbal memory forms a community with working memory and fluency. The behavioral nodes do not differentiate between groups or form clusters with cognitive nodes. No other communities were found for cognitive and behavioral nodes.

CONCLUSION

The cognitive phenotype of the frontal lobe damaged group, with its stability and proportion, might be theoretically interpreted as a potential "buffer" for possible cognitive executive deficits. This might explain some of the ambiguity found in the literature. This alternative approach on cognitive test scores provides a different and possibly complimentary perspective of the neuropsychology of brain-injured patients.

Influence of age and education on the processing of clustering and switching in verbal fluency tasks

Verbal fluency (VF) is a widely used tool in neuropsychological assessment.

The Neuropsychological Function of Older First-Time Child Exploitation Material Offenders: A Pilot Study

Despite the growing incidence of child exploitation offences, there is little knowledge of the neuropsychological function of older child exploitation material offenders (CEMOs). Given that studies have reported that sex offenders demonstrate deficits attributed to frontal and temporal lobe function, the aim of this pilot study was to investigate the frontotemporal function of older first-time child exploitation material offenders (FTCEMOs). The neuropsychological performance of 11 older FTCEMOs was compared with 34 older historical sex offenders (HSOs) and 32 older nonsex offender (NSO) controls. Forty-five percent of FTCEMOs admitted to a pedophilic interest, which was significantly lower than those reported by HSOs. FTCEMOs provided significantly higher intellectual function scores than HSOs. Results revealed no evidence of mild or major neurocognitive disorder in FTCEMOs. Although the groups were not significantly different, compared with normative data, FTCEMOs reported a high incidence of impairment on a measure of decision making and on a measure of facial emotional recognition.

Processing speed and the relationship between Trail Making Test-B performance, cortical thinning and white matter microstructure in older adults

Part B of the Trail Making Test (TMT-B) is widely used as a quick and easy to administer measure of executive dysfunction. The current study investigated the relationships between TMT-B performance, brain volumes, cortical thickness and white matter water diffusion characteristics in a large sample of older participants, before and after controlling for processing speed. Four hundred and eleven healthy, community-dwelling older adults who were all born in 1936 were assessed on TMT-B, 5 tests of processing speed, and provided contemporaneous structural and diffusion MRI data. Significant relationships were found between slower TMT-B completion times and thinner cortex in the frontal, temporal and inferior parietal regions as well as the Sylvian fissure/insula. Slower TMT-B completion time was also significantly associated with poorer white matter microstructure of the left anterior thalamic radiation, and the right uncinate fasciculus. The majority of these associations were markedly attenuated when additionally controlling for processing speed. These data suggest that individual differences in processing speed contribute to the associations between TMT-B completion time and the grey and white matter structure of older adults.

Inattention and impulsivity associated with prenatal alcohol exposure in a prospective cohort study with 11-years-old Brazilian children

This paper aimed to examine prenatal alcohol exposure and neuropsychological parameters and its relationship to impulsivity and inattention. Longitudinal prospective case-control cohort study starting with the risk drinking assessment of 449 third-trimester pregnant women, and a follow-up phase with 56 mother-child pairs (28 alcohol-exposed versus 28 non-exposed), with 11-12 years old children. The cohort study was followed up for 11 years. Quantity-frequency structured questions as well as AUDIT and T-ACE questionnaires were used to assess maternal alcohol consumption. A comprehensive set of neuropsychological testing instruments was used, including d2 Test, RCFT, RAVLT, WISC-III, among others. To control low IQ effects and intellectual disability diagnoses, as well differences in school skills biasing the neuropsychological comparison assessment, children with IQ <70 or learning disabilities were excluded of the sample. The two groups showed to be very comparable regarding sex, age, schooling, global IQ, laterality and maternal and social risk factors. Significant statistical differences were found for higher speed processing, total errors, and number of omission errors in the d2 Test. Likewise, there were differences found on RCFT test (lower scores for copy, immediate and delayed recall), and on semantic verbal fluency tests with a lower score. Prenatal alcohol-exposed children seems to be more inattentive and impulsive; they have poorer skills in verbal fluency, visuospatial working memory, and executive processing when compared to non-exposed children who were part of the same cohort sample.

Performance of Children in Phonemic and Semantic Verbal Fluency Tasks

Abstract This study investigated the performance of children from the Brazilian Northeast region, from 7 to 10 years in phonemic and semantic verbal fluency tasks. The participants were 102 subjects (62 girls and 40 boys) who performed three phonemic and three semantic fluency tasks. The results were submitted to correlational and variance analysis to investigate the influence of the variables age and gender on the subjects performance. There was no effect of gender on the results. Significant contrasts between age groups were found, and better performance was observed on phonemic tasks. Also, the performance in this task changed along development, in contrast to what happened with the semantic fluency. The findings seem to be in accordance to neurodevelopmental aspects, taken into account that explicit memory systems show more precocious maturational course, with earlier consolidation, in comparison to the executive functions and frontal lobes, which go on developing until adult ages.

Brazilian Normative Data on Letter and Category Fluency Tasks: Effects of Gender, Age, and Geopolitical Region

Verbal fluency is a basic function of language that refers to the ability to produce fluent speech. Despite being an essentially linguistic function, its measurements are also used to evaluate executive aspects of verbal behavior. Performance in verbal fluency (VF) tasks varies according to age, education, and cognitive development. Neurodevelopmental disorders that affect the functioning of frontal areas tend to cause lower performance in VF tasks. Despite the relative consensus that has been reached in terms of the use of VF tasks for the diagnosis of dyslexia and attention-deficit/hyperactivity disorder, few studies have considered regional variations in Brazil. The present study sought to provide normative data on VF tasks in children by considering gender, age, education, and geopolitical region of origin with auxiliary purposes in neuropsychological diagnosis of disorders that occur with executive changes The study included 298 participants, 7–10 years of age of both genders, who performed three letter fluency tasks and three category fluency tasks. The data were subjected to correlational and variance analyses, with age and gender as factors. No effect of gender on the children's performance was found. However, significant differences between age groups were observed, with better performance in letter tasks in older children and better performance in letter tasks compared with category tasks. Significant regional differences in performance on the letter VF task were observed. These results reinforce the importance of regional normative data in countries with high regional cultural variations, such as Brazil.

Altered Resting-State Connectivity within Executive Networks after Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with significant mortality rates, and most survivors experience significant cognitive deficits across multiple domains, including executive function. It is critical to determine the neural basis for executive deficits in aSAH, in order to better understand and improve patient outcomes. This study is the first examination of resting-state functional Magnetic Resonance Imaging in a group of aSAH patients, used to characterize changes in functional connectivity of the frontoparietal network. We scanned 14 aSAH patients and 14 healthy controls, and divided patients into “impaired” and “unimpaired” groups based on a composite executive function score. Impaired patients exhibited significantly lower quality of life and neuropsychological impairment relative to controls, across multiple domains. Seed-based functional connectivity analysis demonstrated that unimpaired patients were not significantly different from controls, but impaired patients had increased frontoparietal connectivity. Patients evidenced increased frontoparietal connectivity as a function of decreased executive function and decreased mood (i.e. quality of life). In addition, T1 morphometric analysis demonstrated that these changes are not attributable to local cortical atrophy among aSAH patients. These results establish significant, reliable changes in the endogenous brain dynamics of aSAH patients, that are related to cognitive and mood outcomes.

Limitations of the trail making test part-B in assessing frontal executive dysfunction

Part B of the Trail Making Test (TMT-B) is one of the most widely used neuropsychological tests of "executive" function. A commonly held assumption is that the TMT-B can be used to detect frontal executive dysfunction. However, so far, research evidence has been limited and somewhat inconclusive. In this retrospective study, performance on the TMT-B of 55 patients with known focal frontal lesions, 27 patients with focal non-frontal lesions and 70 healthy controls was compared. Completion time and the number of errors made were examined. Patients with frontal and non-frontal lesions performed significantly worse than healthy controls for both completion time and the number of errors. However, there was no significant difference for both completion time and the number of errors when patients with frontal and non-frontal lesions were compared. Performance was also not significantly different between patients with focal lesions within different regions of the frontal lobe (orbital, left lateral, right lateral, medial). Our findings suggest that the TMT-B is a robust test for detection of brain dysfunction. However, its capacity for detecting frontal executive dysfunction appears rather limited. Clinicians should be cautious when drawing conclusions from performance on the TMT-B alone.

Episodic future thinking: linking neuropsychological performance with episodic detail in young and old adults

Episodic future thinking (EFT) has been linked with our ability to remember past events. However, its specific neurocognitive subprocesses have remained elusive. In Experiment 1, a study of healthy older adults was conducted to investigate the candidate subprocesses of EFT. Participants completed a standard EFT cue word task, two memory measures (Verbal Paired Associates I, Source Memory), and two measures of executive function (Trail Making Test, Tower Test). In Experiment 2, healthy young adults also completed an EFT task and neuropsychological measures. The link between neurocognitive measures and five characteristics of EFT was investigated. Specifically, it was found that Source Memory and Trail Making Test performance predicted the episodic specificity of future events in older but not younger adults. Replicating previous findings, older adults produced future events with greater semantic but fewer episodic details than did young adults. These results extend the data and emphasize the importance of the multiple subprocesses underlying EFT.

Comparison of Neuropsychological Performance between Students from Public and Private Brazilian Schools

Neuropsychological assessment reveals that certain cognitive changes that take place during the neural development process may be associated with biopsychosocial issues. A substantial body of research has focused on cognitive development in children and adults, but few such studies have been carried out on adolescents. Therefore, research into the processing of neuropsychological functions in adolescents, taking into account the role of major socio-cultural factors such as school type (public vs. private), is highly relevant. The present study sought to assess whether differences in neuropsychological development exist between adolescent students of public (government-funded) and private schools. A total of 373 grade-matched students between the ages of 12 and 18, 190 from public schools and 183 from private schools, took part in the study. All subjects had no self-reported neurologic or psychiatric conditions and sensory disorders. The NEUPSILIN Brazilian Brief Neuropsychological Assessment Battery was administered to this sample. Comparison of mean scores (one-way ANCOVA with socioeconomic score and age as covariates) showed that adolescents attending private schools generally outperformed their public-school peers in tasks involving sustained attention, memory (working and visual), dictated writing, and constructional and reflective abilities. We conclude that school type should be taken into account during standardization of neuropsychological assessment instruments for adolescent and, probably, child populations.

Executive functioning and depressed mood before and after unilateral frontal lobe resection for intractable epilepsy

Executive dysfunction occurs in a variety of patients who have sustained damage to the frontal lobes. In individuals with frontal lobe epilepsy (FLE) or after unilateral frontal lobe resection (FLR), a unique neuropsychological profile linking executive functions (EF) with the frontal lobe has been elusive, with conflicting findings in the literature. Some studies show greater risk of executive impairment with left-sided FLE or FLR, while others report greater risk for right-sided patients. Some studies report no relationship between FLE and EF impairment, while others show EF impairment regardless of side of seizure foci or surgery. In patients with temporal lobe epilepsy, executive dysfunction is associated with depressed mood possibly reflecting disruption of cortical-limbic pathways and/or frontal-striatal circuitry. Although not previously examined, depression level may affect executive functioning in those with FLE or FLR. We hypothesized that FLE patients with poor mood state would show greater executive dysfunction than FLE patients without poor mood state. The relationship among EF, side of surgery and depressed mood before and 8 months after unilateral FLR was evaluated in 64 patients using validated measures of EF and mood state (Beck Depression Inventory-II). Results indicated that individuals with depressed mood before surgery had greater difficulty on a task of mental flexibility compared to patients without preoperative depressed mood. Further, individuals with depressed mood before surgery had significant increases in perseverative responding and completed fewer categories on a card-sorting task after surgery compared to patients without preoperative depressed mood. Regression analyses showed that among side of surgery, seizure freedom status after surgery and depression status, only pre-surgical depression status explained a significant amount of variance in executive functioning performance after surgery. Results suggest that clinically elevated depressive symptoms before surgery are a risk factor for moderate declines in EF after surgery. Results may be attributable to reduced cognitive reserve in patients with depressive symptoms, or may reflect a common cause attributable to damage to unilateral dorsal and ventral lateral frontal lobe.

Executive function on the Psychology Experiment Building Language tests

The measurement of executive function has a long history in clinical and experimental neuropsychology. The goal of the present report was to determine the profile of behavior across the lifespan on four computerized measures of executive function contained in the recently developed Psychology Experiment Building Language (PEBL) test battery http://pebl.sourceforge.net/ and evaluate whether this pattern is comparable to data previously obtained with the non-PEBL versions of these tests. Participants (N = 1,223; ages, 5-89 years) completed the PEBL Trail Making Test (pTMT), the Wisconsin Card Sort Test (pWCST; Berg, Journal of General Psychology, 39, 15-22, 1948; Grant & Berg, Journal of Experimental Psychology, 38, 404-411, 1948), the Tower of London (pToL), or a time estimation task (Time-Wall). Age-related effects were found over all four tests, especially as age increased from young childhood through adulthood. For several tests and measures (including pToL and pTMT), age-related slowing was found as age increased in adulthood. Together, these findings indicate that the PEBL tests provide valid and versatile new research tools for measuring executive functions.

Right frontal lobe mediation of recollection- and familiarity-based verbal recognition memory: evidence from patients with tumor resections

Medial-temporal, parietal, and pFC regions have been implicated in recollection and familiarity, but existing evidence from neuroimaging and patient studies is limited and conflicting regarding the role of specific regions within pFC in these memory processes. We report a study of 20 patients who had undergone resection of right frontal lobe tumors and 20 matched healthy control participants. The location and extent of lesions were traced on the patients' scans. A process dissociation procedure was employed to yield estimates of the contributions of recollection and familiarity in verbal recognition performance. Group comparisons revealed deficits in recollection but not familiarity in the patient group relative to their healthy counterparts. We found a positive relationship between estimates of familiarity and lesion sizes in the right inferior pFC (BA 11, 47) which was significant upon bootstrap resampling. These results are discussed in terms of prior work linking this area to an overextended sense of familiarity.

Wisconsin card sorting test as a measure of executive function impairments in stroke patients

The Wisconsin Card Sorting Test (WCST) is among the most frequently administered neuropsychological tests. It is assumed that successful completion of this test requires engagement of executive functions (EF). One of the most common origins of EF impairments is ischemic stroke. The present study intends to evaluate the diagnostic use of the WCST as a measure of these impairments in poststroke patients. Forty-four patients (8 women and 36 men) who had recent unilateral stroke (22 left hemisphere, 22 right hemisphere) participated in the study. The overall accuracy of the WCST in classifying stroke survivors as having executive disorders was poor. Nevertheless, statistical analysis revealed its negative predictive power to be greater than positive predictive power (i.e., normal scores on the WCST reliably indicated the absence of executive disorders in 8 or more out of 10). Performance on the WCST is clearly influenced by severity of the executive disorders. Namely, patients with severe impairment of EF (as measured by go/no-go, fluency, and other EF tests) performed more poorly on the WCST than patients with lesser impairment or those with no impairment at all, the latter group's results being indistinguishable. In addition, this study highlights a three-factor solution to the WCST, which accounted for 90.3% of the variance. The scores that most strongly loaded on Factors 1 to 3 were, in order: percentage of conceptual-level responses, number of trials to complete the first category, and failures to maintain the set of responses. Finally, an analysis using multivariate analysis of variance, with the anterior versus posterior site and left versus right side of the lesion as independent variables, revealed a relatively weak effect of lesion location on the WCST performance. In particular, with respect to all test scores, there is only one significant interaction between the site and side of lesion was obtained (F(₁(,)₂₄) = 4.12; p < .05; i.e., the number of categories achieved was significantly smaller after damage to the frontal lobe on the left than on the right side, whereas the laterality effect was not significant after nonfrontal lesions). In conclusion, to ascertain the cerebral substrates of poststroke executive dysfunction, there is a need to apply more accurate tests than the WCST. The study highlights the importance of a multicomponent approach to executive functioning in stroke patients.

Executive function and fluid intelligence after frontal lobe lesions

Many tests of specific 'executive functions' show deficits after frontal lobe lesions. These deficits appear on a background of reduced fluid intelligence, best measured with tests of novel problem solving. For a range of specific executive tests, we ask how far frontal deficits can be explained by a general fluid intelligence loss. For some widely used tests, e.g. Wisconsin Card Sorting, we find that fluid intelligence entirely explains frontal deficits. When patients and controls are matched on fluid intelligence, no further frontal deficit remains. For these tasks too, deficits are unrelated to lesion location within the frontal lobe. A second group of tasks, including tests of both cognitive (e.g. Hotel, Proverbs) and social (Faux Pas) function, shows a different pattern. Deficits are not fully explained by fluid intelligence and the data suggest association with lesions in the right anterior frontal cortex. Understanding of frontal lobe deficits may be clarified by separating reduced fluid intelligence, important in most or all tasks, from other more specific impairments and their associated regions of damage.