Neuroanatomical correlates of executive functions: a neuropsychological approach using the EXAMINER battery

Left and right corticobasal syndrome: comparison of cognitive profiles between metabolic imaging - matched groups

BACKGROUND

Corticobasal syndrome (CBS) is typically asymmetric. Case reports suggest that left-hemisphere CBS (lhCBS) is associated with major language impairment, and right-hemisphere CBS (rhCBS) is associated with major visuospatial deficits, but no group study has ever verified these observations. In our study, we enrolled 49 patients with CBS, classified them as lhCBS or rhCBS based on asymmetry of hypometabolism on brain FDG-PET and compared their cognitive and behavioural profiles.

METHODS

We defined asymmetry of hypometabolism upon visual inspection of qualitative PET images and confirmed it through paired comparison of left- and right-hemisphere FDG uptake values. The two groups were also matched for severity of hypometabolism within the more affected and more preserved hemispheres, to unravel differences in the cognitive profiles ascribable specifically to each hemisphere's functional specializations. All patients were assessed for memory, language, executive and visuospatial deficits, apraxia, neglect, dyscalculia, agraphia and behavioural disturbances.

RESULTS

LhCBS (n. 26) and rhCBS (n. 23) patients did not differ for demographics, disease duration and severity of global cognitive impairment. The two cognitive profiles were largely overlapping, with two exceptions: Digit span forward was poorer in lhCBS, and visual neglect was more frequent in rhCBS.

CONCLUSIONS

After balancing out patients for hemispheric hypometabolism, we did not confirm worse language or visuospatial deficits in, respectively, lhCBS and rhCBS. However, verbal short-term memory was more impaired in lhCBS, and spatial attention was more impaired in rhCBS. Both of these functions reflect the functional specialization of the left and right fronto-parietal pathways, i.e. of the main loci of neurodegeneration in CBS.

Cognitive function based on theta-gamma coupling vs. clinical diagnosis in older adults with mild cognitive impairment with or without major depressive disorder

Whether individuals with mild cognitive impairment (MCI) and a history of major depressive disorder (MDD) are at a higher risk for cognitive decline than those with MCI alone is still not clear. Previous work suggests that a reduction in prefrontal cortical theta phase-gamma amplitude coupling (TGC) is an early marker of cognitive impairment. This study aimed to determine whether using a TGC cutoff is better at separating individuals with MCI or MCI with remitted MDD (MCI+rMDD) on cognitive performance than their clinical diagnosis. Our hypothesis was that global cognition would differ more between TGC-based groups than diagnostic groups. We analyzed data from 128 MCI (mean age: 71.8, SD: 7.3) and 85 MCI+rMDD (mean age: 70.9, SD: 4.7) participants. Participants completed a comprehensive neuropsychological battery; TGC was measured during the N-back task. An optimal TGC cutoff was determined during the performance of the 2-back. This TGC cutoff was used to classify participants into low vs. high-TGC groups. We then compared Cohen's d of the difference in global cognition between the high and low TGC groups to Cohen's d between the MCI and MCI+rMDD groups. We used bootstrapping to determine 95% confidence intervals for Cohen's d values using the whole sample. As hypothesized, Cohen's d for the difference in global cognition between the TGC groups was larger (0.64 [0.32, 0.88]) than between the diagnostic groups (0.10 [0.004, 0.37]) with a difference between these two Cohen's d's of 0.54 [0.10, 0.80]. Our findings suggest that TGC is a useful marker to identify individuals at high risk for cognitive decline, beyond clinical diagnosis. This could be due to TGC being a sensitive marker of prefrontal cortical dysfunction that would lead to an accelerated cognitive decline.

Economic and social values in the brain: evidence from lesions to the human ventromedial prefrontal cortex

Making good economic and social decisions is essential for individual and social welfare. Decades of research have provided compelling evidence that damage to the ventromedial prefrontal cortex (vmPFC) is associated with dramatic personality changes and impairments in economic and social decision-making. However, whether the vmPFC subserves a unified mechanism in the social and non-social domains remains unclear. When choosing between economic options, the vmPFC is thought to guide decision by encoding value signals that reflect the motivational relevance of the options on a common scale. A recent framework, the "extended common neural currency" hypothesis, suggests that the vmPFC may also assign values to social factors and principles, thereby guiding social decision-making. Although neural value signals have been observed in the vmPFC in both social and non-social studies, it is yet to be determined whether they have a causal influence on behavior or merely correlate with decision-making. In this review, we assess whether lesion studies of patients with vmPFC damage offer evidence for such a causal role of the vmPFC in shaping economic and social behavior.

Apathy in Patients With Cerebral Amyloid Angiopathy: A Multimodal Neuroimaging Study

BACKGROUND AND OBJECTIVE

To analyze the prevalence and associated clinical characteristics of apathy in sporadic cerebral amyloid angiopathy and investigate whether apathy was associated with disease burden and disconnections of key structures in the reward circuit through a structural and functional multimodal neuroimaging approach.

METHODS

Thirty-seven participants with probable sporadic cerebral amyloid angiopathy without symptomatic intracranial hemorrhage or dementia (mean age, 73.3 ± 7.2 years, % male = 59.5%) underwent a detailed neuropsychological evaluation, including measures of apathy and depression, and a multimodal MR neuroimaging study. A multiple linear regression analysis was used to assess the association of apathy with conventional small vessel disease neuroimaging markers. A voxel-based morphometry with a small volume correction within regions previously associated with apathy and a whole-brain tract-based spatial statistics were performed to identify differences in the gray matter and white matter between the apathetic and nonapathetic groups. Gray matter regions significantly associated with apathy were further evaluated for their functional alterations as seeds in the seed-based resting-state functional connectivity analysis. Potential confounders, namely, age, sex, and measures of depression, were entered as covariates in all analyses.

RESULTS

A higher composite small vessel disease marker score (CAA-SVD) was associated with a higher degree of apathy (standardized coefficient = 1.35 (0.07-2.62), adjusted R2 = 27.90, p = 0.04). Lower gray matter volume of the bilateral orbitofrontal cortices was observed in the apathetic group than in the nonapathetic group (F = 13.20, family-wise error-corrected p = 0.028). The apathetic group demonstrated a widespread decrease in white matter microstructural integrity compared with the nonapathetic group. These tracts connect key regions within and between related reward circuits. Finally, there were no significant functional alterations between the apathetic and nonapathetic groups.

DISCUSSION

Our findings revealed the orbitofrontal cortex as a key region in the reward circuit associated with apathy in sporadic cerebral amyloid angiopathy, independent from depression. Apathy was shown to be associated with a higher CAA-SVD score and an extensive disruption of white matter tracts, which suggested that a higher burden of CAA pathology and the disruption in large-scale white matter networks may underlie manifestations of apathy.

Large-scale lesion symptom mapping of depression identifies brain regions for risk and resilience

Understanding neural circuits that support mood is a central goal of affective neuroscience, and improved understanding of the anatomy could inform more targeted interventions in mood disorders. Lesion studies provide a method of inferring the anatomical sites causally related to specific functions, including mood. Here, we performed a large-scale study evaluating the location of acquired, focal brain lesions in relation to symptoms of depression. Five hundred and twenty-six individuals participated in the study across two sites (356 male, average age 52.4 ± 14.5 years). Each subject had a focal brain lesion identified on structural imaging and an assessment of depression using the Beck Depression Inventory-II, both obtained in the chronic period post-lesion (>3 months). Multivariate lesion-symptom mapping was performed to identify lesion sites associated with higher or lower depression symptom burden, which we refer to as 'risk' versus 'resilience' regions. The brain networks and white matter tracts associated with peak regional findings were identified using functional and structural lesion network mapping, respectively. Lesion-symptom mapping identified brain regions significantly associated with both higher and lower depression severity (r = 0.11; P = 0.01). Peak 'risk' regions include the bilateral anterior insula, bilateral dorsolateral prefrontal cortex and left dorsomedial prefrontal cortex. Functional lesion network mapping demonstrated that these 'risk' regions localized to nodes of the salience network. Peak 'resilience' regions include the right orbitofrontal cortex, right medial prefrontal cortex and right inferolateral temporal cortex, nodes of the default mode network. Structural lesion network mapping implicated dorsal prefrontal white matter tracts as 'risk' tracts and ventral prefrontal white matter tracts as 'resilience' tracts, although the structural lesion network mapping findings did not survive correction for multiple comparisons. Taken together, these results demonstrate that lesions to specific nodes of the salience network and default mode network are associated with greater risk versus resiliency for depression symptoms in the setting of focal brain lesions.

Executive functions in primary progressive aphasia: A meta-analysis

Executive functions (EFs) refer to a set of cognitive processes, specifically shifting, inhibition, updating of working memory, and are involved in the cognitive control of behavior. Conflicting results have been reported regarding impairments of EFs in Primary Progressive Aphasia (PPA). We performed a multi-level meta-analysis to confirm whether deficits of EFs exist in this population, focusing on a common EFs composite, and the components shifting, inhibition and updating separately. We included 141 studies that report on 294 EFs tasks. The overall mean weighted effect size was large (d = -1,28), indicating poorer EFs in PPA as compared to age-matched cognitively healthy controls. Differences between effect sizes of the EFs components were not significant, indicating all components are affected similarly. Overall, moderator analysis revealed that PPA variant and disease duration were significant moderators of performance, while task modality and years of education were not. The non-fluent/agrammatic PPA and the logopenic PPA variants were similarly affected, but the semantic variant was affected to a lesser extent. We discuss implications for clinical and research settings, and future research.

Fronto-Parietal and White Matter Haemodynamics Predict Cognitive Outcome in Children with Moyamoya Independent of Stroke

Moyamoya disease is a major arteriopathy characterised by progressive steno-occlusion of the arteries of the circle of Willis. Studies in adults with moyamoya suggest an association between abnormal fronto-parietal and white matter regional haemodynamics and cognitive impairments, even in the absence of focal infarction. However, these associations have not been investigated in children with moyamoya. We examined the relationship between regional haemodynamics and ratings of intellectual ability and executive function, using hypercapnic challenge blood oxygen level-dependent magnetic resonance imaging of cerebrovascular reactivity in a consecutive cohort of children with confirmed moyamoya. Thirty children were included in the final analysis (mean age: 12.55 ± 3.03 years, 17 females, 15 idiopathic moyamoya and 15 syndromic moyamoya). Frontal haemodynamics were abnormal in all regardless of stroke history and comorbidity, but occipital lobe haemodynamics were also abnormal in children with syndromic moyamoya. Executive function deficits were noted in both idiopathic and syndromic moyamoya, whereas intellectual ability was impaired in syndromic moyamoya, even in the absence of stroke. Analysis of the relative effect of regional abnormal haemodynamics on cognitive outcomes demonstrated that executive dysfunction was predominantly explained by right parietal and white matter haemodynamics independent of stroke and comorbidity, while posterior circulation haemodynamics predicted intellectual ability. These results suggest that parietal and posterior haemodynamics play a compensatory role in overcoming frontal vulnerability and cognitive impairment.

Spontaneous brain activity, graph metrics, and head motion related to prospective post-traumatic stress disorder trauma-focused therapy response

Introduction

Trauma-focused psychotherapy for post-traumatic stress disorder (PTSD) is effective in about half of all patients. Investigating biological systems related to prospective treatment response is important to gain insight in mechanisms predisposing patients for successful intervention. We studied if spontaneous brain activity, brain network characteristics and head motion during the resting state are associated with future treatment success.

Methods

Functional magnetic resonance imaging scans were acquired from 46 veterans with PTSD around the start of treatment. Psychotherapy consisted of trauma-focused cognitive behavioral therapy (tf-CBT), eye movement desensitization and reprocessing (EMDR), or a combination thereof. After intervention, 24 patients were classified as treatment responders and 22 as treatment resistant. Differences between groups in spontaneous brain activity were evaluated using amplitude of low-frequency fluctuations (ALFF), while global and regional brain network characteristics were assessed using a minimum spanning tree (MST) approach. In addition, in-scanner head motion was assessed.

Results

No differences in spontaneous brain activity and global network characteristics were observed between the responder and non-responder group. The right inferior parietal lobule, right putamen and left superior parietal lobule had a more central position in the network in the responder group compared to the non-responder group, while the right dorsolateral prefrontal cortex (DLPFC), right inferior frontal gyrus and left inferior temporal gyrus had a less central position. In addition, responders showed less head motion.

Discussion

These results show that areas involved in executive functioning, attentional and action processes, learning, and visual-object processing, are related to prospective PTSD treatment response in veterans. In addition, these findings suggest that involuntary micromovements may be related to future treatment success.

Lesions in different prefrontal sectors are associated with different types of acquired personality disturbances

"Frontal lobe syndrome" is a term often used to describe a diverse array of personality disturbances following frontal lobe damage. This study's guiding premise was that greater neuroanatomical specificity could be achieved by evaluating specific types of personality disturbances following acquired frontal lobe lesions. We hypothesized that three acquired personality disturbances would be associated with lesion involvement of distinct sectors of the prefrontal cortex (PFC): 1) emotional-social disturbance and ventromedial PFC, 2) hypoemotional disturbance and dorsomedial PFC, and 3) dysexecutive and dorsolateral PFC. In addition, we hypothesized that distressed personality disturbance would not be associated with focal PFC lesions in any sector. Each hypothesis was pre-registered and tested in 182 participants with adult-onset, chronic, focal brain lesions studied with an observational, cross-sectional design. Pre- and postmorbid personality was assessed by informant-rating with the Iowa Scales of Personality Change, completed by a spouse or family member. Two complementary analytic approaches were employed: 1) a hypothesis-driven region-of-interest (ROI) regression analysis examining the associations of lesions in specific PFC sectors with acquired personality disturbances; 2) a data-driven multivariate lesion-behavior mapping analysis, which was not limited to pre-specified regions. Each hypothesis received some support: (i) Emotional/social personality disturbance was most strongly associated with ventromedial PFC lesions in both statistical approaches. (ii) Hypoemotional disturbance was associated with dorsomedial PFC lesions in the ROI analyses, without any significant lesion-symptom mapping associations. (iii) Dysexecutive personality disturbance was associated with bilateral dorsolateral PFC lesions and ventromedial PFC lesions; lesion-symptom mapping showed maximal association of executive dysfunction with damage of the right middle frontal gyrus within the dorsolateral PFC. (iv) Distressed personality disturbance was not associated with lesions in any PFC sector. Altogether, the findings can be interpreted to indicate that damage to different prefrontal sectors may disrupt different anatomical-functional systems and result in distinct personality disturbances.

Age- and Sex-Related Topological Organization of Human Brain Functional Networks and Their Relationship to Cognition

Age and sex associated with changes in the functional brain network topology and cognition in large population of older adults have been poorly understood. We explored this question further by examining differences in 11 resting-state graph theory measures with respect to age, sex, and their relationships with cognitive performance in 17,127 United Kingdom Biobank participants (mean = 62.83 ± 7.41 years). Age was associated with an overall decrease in the effectiveness of network communication (i.e., integration) and loss of functional specialization (i.e., segregation) of specific brain regions. Sex differences were also observed, with women showing more efficient networks, which were less segregated than in men (FDR adjusted p < 0.05). The age-related changes were also more apparent in men than in women, which suggests that men may be more vulnerable to cognitive decline with age. Interestingly, while network segregation and strength of limbic network were only nominally associated with cognitive performance, the network measures collectively were significantly associated with cognition (FDR adjusted p ≤ 0.002). This may imply that individual measures may be inadequate to capture much of the variance in the neural activity or its output and need further refinement. The complexity of the organization of the functional brain may be shaped by the age and sex of an individual, which ultimately may influence the cognitive performance of older adults. Age and sex stratification may be used to inform clinical neuroscience research to identify older adults at risk of cognitive dysfunction.

Interbatch Reliability of Blood-Based Cytokine and Chemokine Measurements in Community-Dwelling Older Adults: A Cross-Sectional Study

Blood-based inflammatory markers hold considerable promise for diagnosis and prognostication of age-related neurodegenerative disease, though a paucity of research has empirically tested how reliably they can be measured across different experimental runs ("batches"). We quantified the interbatch reliability of 13 cytokines and chemokines in a cross-sectional study of 92 community-dwelling older adults (mean age = 74; 48% female). Plasma aliquots from the same blood draw were parallelly processed in 2 separate batches using the same analytic platform and procedures (high-performance electrochemiluminescence by Meso Scale Discovery). Interbatch correlations (Pearson's r) ranged from small and nonsignificant (r = .13 for macrophage inflammatory protein-1 alpha [MIP-1α]) to very large (r > .90 for interferon gamma [IFNγ], interleukin-10 [IL-10], interferon gamma-induced protein 10 [IP-10], MIP-1β, thymus and activation-regulated chemokine [TARC]) with most markers falling somewhere in between (.67 ≤ r ≤ .90 for IL-6, tumor necrosis factor alpha [TNF-α], Eotaxin, Eotaxin-3, monocyte chemoattractant protein-1 [MCP-1], MCP-4, macrophage-derived chemokine [MDC]). All markers, except for IL-6 and MCP-4, showed significant differences in absolute values between batches, with discrepancies ranging in effect size (Cohen's d) from small to moderate (0.2 ≤ |d| ≤ 0.5 for IL-10, IP-10, MDC) to large or very large (0.68 ≤ |d| ≤ 1.5 for IFNγ, TNF-α, Eotaxin, Eotaxin-3, MCP-1, MIP-1α, MIP-1β, TARC). Relatively consistent associations with external variables of interest (age, sex, systolic blood pressure, body mass index, cognition) were observed across batches. Taken together, our results suggest heterogeneity in measurement reliability of blood-based cytokines and chemokines, with some analytes outperforming others. Future work is needed to evaluate the generalizability of these findings while identifying potential sources of batch effect measurement error.

Comparing the Executive Function Ability of Autistic and Non-autistic Adolescents with a Manualised Battery of Neuropsychological Tasks

Performance on a single executive function (EF) task (e.g., a card sorting task) is often taken to represent ability on the underlying subcomponent of EF (e.g., set shifting) without accounting for the non-specific and non-executive skills employed to complete the task. This study used a manualised battery of EF tasks to derive individual task scores and latent EF scores. Seventy-nine adolescents aged between 11 and 19 years, including 37 autistic and 42 non-autistic participants, matched on cognitive ability, completed the battery. Autistic adolescents had moderate global EF difficulties and had significantly more difficulties on some individual tasks. However, the samples did not differ on any of the specific individual subcomponents of EF (fluency, cognitive control and working memory).

Widespread white matter aberration is associated with the severity of apathy in amnestic Mild Cognitive Impairment: Tract-based spatial statistics analysis

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In aMCI, apathy severity was associated with lower FA in widespread WM pathways.

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WM aberrations are related to apathy severity after controlling for depression.

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Disruptions related to apathy severity are not limited to frontal-subcortical area.

Apathy is recognized as a prevalent behavioral symptom of amnestic Mild Cognitive Impairment (aMCI). In aMCI, apathy is associated with an increased risk and increases the risk of progression to Alzheimer’s Disease (AD). Previous DTI study in aMCI showed that apathy has been associated with white matter alterations in the cingulum, middle and inferior longitudinal fasciculus, fornix, and uncinate fasciculus. However, the underlying white matter correlates associated with apathy in aMCI are still unclear. We investigated this relationship using whole-brain diffusion tensor imaging (DTI). Twenty-nine aMCI patients and 20 matched cognitively healthy controls were included. Apathy severity was assessed using the Apathy Evaluation Scale Clinician version. We applied the tract-based spatial statistics analyses to DTI parameters: fractional anisotropy (FA), mean diffusivity, axial diffusivity, and radial diffusivity to investigate changes in white matter pathways associated with the severity of apathy. No significant difference was found in any of the DTI parameters between aMCI and the control group. In aMCI, higher severity of apathy was associated with lower FA in various white matter pathways including the left anterior part of inferior fronto-occipital fasciculus/uncinate fasciculus, genu and body of the corpus callosum, superior and anterior corona radiata, anterior thalamic radiation of both hemispheres and in the right superior longitudinal fasciculus/anterior segment of arcuate fasciculus (p < .05, TFCE-corrected) after controlling for age, gender and GDS non-apathy. A trend association was observed in the right posterior corona radiata and corticospinal tract/internal capsule, and bilateral forceps minor (p < .065, TFCE-corrected). In conclusion, in aMCI, severity of apathy is associated with aberrant white matter integrity in widely distributed pathways, within and between hemispheres.

The Neurological Predictor Scale Predicts Adaptive Functioning via Executive Dysfunction in Young Adult Survivors of Childhood Brain Tumor

OBJECTIVES

Survivors of childhood brain tumors experience neurological sequelae that disrupt everyday adaptive functioning (AF) skills. The Neurological Predictor Scale (NPS), a cumulative measure of tumor treatments and sequelae, predicts cognitive outcomes, but findings on its relation to informant-reported executive dysfunction (ED) and AF are mixed. Given known effects of frontal-subcortical system disruptions on AF, this study assessed the NPS' relationship with AF as mediated by frontal systems dysfunction, measured by the Frontal Systems Behavior Scale (FrSBe).

METHODS

75 participants (Mage = 23.5, SDage = 4.5) were young adult survivors of childhood brain tumors at least 5 years past diagnosis. FrSBe and Scales of Independent Behavior-Revised (SIB-R), a measure of AF, were administered to informants. Parallel multiple mediator models included Apathy and ED as mediators, and age at diagnosis and time between diagnosis and assessment as covariates.

RESULTS

More complex treatment and sequelae were correlated with poorer functioning. Mediation models were significant for all subscales: Motor Skills (MS), p = .0001; Social Communication (SC), p = .002; Personal Living (PL), p = .004; Community Living (CL), p = .007. The indirect effect of ED on SC and CL was significant; the indirect effect of Apathy was not significant for any subscales.

CONCLUSIONS

More complex tumor treatment and sequelae were associated with poorer long-term AF via increased ED. Cognitive rehabilitation programs may focus on the role of executive function and initiation that contribute to AF, particularly SC and CL skills, to help survivors achieve comparable levels of independence in everyday function as their peers.

Differences in dual task paradigms and executive function ability for recreational athletes in United Arab Emirates

[Purpose] The purpose of this study to measure four components of executive function: (1) cognitive flexibility, (2) inhibition, (3) working memory and (4) processing speed, along with the ability to dual task in recreational athletes. [Participants and Methods] This was a cross-sectional study of (n=102) male and female participants, between the ages of 18–40 years of age across different levels and types of sport related physical activity. The International Physical Activity Questionnaire (IPAQ), short version, Dual Task Abilities (DTA) were measured utilizing a quantitative, dual task, gait test and Executive Function (EF) was measured through Stroop Color Word Test and Trail Making Test. [Results] Differences in EF and Dual Task-Interference (DTI) in recreational athletes did not show a significant difference between varying types of sport and level of sport related activity, with reported values high across all groups. Males reported better dual task interference abilities than females, though there were no significant differences in executive function between males and females. Executive function performance was the highest among the age group (18–24 years) population, but there were no significant differences between those in the higher age groups (25–34 years) and (35–40 years). [Conclusion] Overall, those participating in the study exhibited high prevalence of strong EF ability, regardless of sport activity type or level. This may suggest that type and level of sport activity may not be important when considering executive function performance maintenance for recreational athletes.

Changes in Cerebral Volume and White Matter Integrity in Adults on Hemodialysis and Relationship to Cognitive Function

INTRODUCTION

Patients on hemodialysis (HD) have a significant burden of cognitive impairment. Characterizing the cerebral structural changes in HD patients compared to healthy controls and evaluating the relationship of cerebral structural integrity with cognitive performance in HD patients can help clarify the pathophysiology of the cognitive impairment in HD patients.

METHODS

In this cross-sectional study, in-center HD patients ≥50 years of age underwent brain structural and diffusion MRIs and cognitive assessment using the NIH Toolbox cognition battery. The cerebral imaging measures of the HD participants were compared to imaging from age-matched controls. Gray matter volume, white matter volume, and white matter integrity determined by diffusion tensor imaging parameters (including fractional anisotropy [FA]) were measured in both cohorts to determine differences in the cerebral structure between HD participants and healthy controls. The association between cognitive performance on the NIH Toolbox cognition battery and cerebral structural integrity was evaluated using multiple linear regression models.

RESULTS

We compared imaging measures form 23 HD participants and 15 age-matched controls. The HD participants had decreased gray matter volumes (526.8 vs. 589.5 cm3, p < 0.01) and worsened white matter integrity overall (FA values of 0.2864 vs. 0.3441, p < 0.01) within major white matter tracts compared to healthy controls. Decreases in white matter integrity in the left superior longitudinal fasciculus was associated with lower executive function scores (r2 = 0.24, p = 0.02) and inferior longitudinal fasciculus with lower memory scores (r = 0.25 and p = 0.03 for left and r2 = 0.21 and p = 0.03 for right).

CONCLUSIONS

HD patients have a pattern of decreased white matter integrity and gray matter atrophy compared to controls. Decreases in white matter integrity were associated with decreased cognitive performance in the HD population.

Normative data for tests of attention and executive functions in a sample of European Portuguese adult population

OBJECTIVE

The main goal of this study was to produce normative data for the Portuguese population on five neuropsychological tests frequently used to assess executive functions and attention: the Modified Wisconsin Card Sorting Test (M-WCST), the Stroop Color and Word Test, the Trail Making Test (TMT), the Brief Test of Attention (BTA), and the Symbol Digit Modalities Test (SDMT).

METHOD

The study included 300 individuals aged between 18 and 93 years, who had educational backgrounds ranging from 3 to 25 years.

RESULTS

The influence of age, education, and sex was explored for each measure, as well as their contribution to explain the performance variance.

CONCLUSIONS

The normative data are presented as regression-based algorithms to adjust direct and derived test scores for sex, age, and education. This study provides a calculator of normative data, derived from the results of the regression models.

The human cingulum: From the limbic tract to the connectionist paradigm

The cingulum is a core component of the limbic lobe and part of the circuit that was described by Papez where environmental experiences become endowed with emotional awareness. Recent techniques for the study of cerebral connectivity have updated this fasciculus' morphology and led to the acknowledgment that its involvement in superior functions goes far beyond emotion processing. Long and robust, the cingulum is a long association fasciculus with terminations in all cerebral lobes. These observations plead for a pivotal rethinking of its role in the human brain and lead to the conclusion that to merely consider it as the main fasciculus of the limbic system was actually a reductionism. This paper summarizes the key facts regarding why the cingulum is now perceived as a primary interconnecting apparatus in the medial aspect of the cerebral hemisphere.

Transitioning to a microprocessor-controlled prosthetic knee: Executive functioning during single and dual-task gait

BACKGROUND

Walking with a prosthesis requires substantial concentration on behalf of the user and places increased demands on executive functions. Little is known of the effects that prosthetic knee joint prescription may have on executive functioning.

OBJECTIVES

Evaluate executive functioning in trans-femoral prosthesis users during single and dual-task walking, before and after they transition to a Microprocessor-controlled prosthetic knee unit.

STUDY DESIGN

Multiple case-study design.

METHODS

Single and dual task gait was evaluated while recording cortical brain activity. Testing occasion 1 occurred prior to participants receiving their microprocessor-controlled prosthetic knee, while testing occasion 2 was conducted a minimum of 8 months after they had been fitted with an microprocessor-controlled prosthetic knee.

RESULTS

During single-task level walking and walking while performing a dual-task key finding test, executive functions, measured as the relative haemodynamic response in the frontal cortex, reduced for most, but not all participants after transitioning to an Microprocessor-controlled prosthetic knee. There did not appear to be any difference when participants performed a trail walk test.

CONCLUSIONS

Results suggest Microprocessor-controlled prosthetic knee prosthetic knees may have a positive effect on executive functioning for some individuals who have undergone a lower-limb amputation. A larger, longitudinal study with careful control of extraneous variables (e.g. age, training) is needed to confirm results and determine causality.

CLINICAL RELEVANCE

This article provides some evidence to suggest that prosthetic prescription may influence executive functioning and that microprocessor-controlled prosthetic knee mechanisms may reduce cognitive effort when walking.

Exposure to surgery under general anaesthesia and brain magnetic resonance imaging changes in older adults

BACKGROUND

Preclinical studies suggest that exposure to general anaesthesia (GA) could cause neurodegeneration consistent with Alzheimer's disease (AD) pathology. Brain magnetic resonance imaging (MRI) is useful to study structural brain changes. We tested the hypothesis that exposure to surgery with GA (surgery/GA) is associated with greater cortical thinning and increased frequency of white matter lesions.

METHODS

This is a cross-sectional analysis of 70-91-yr-old participants enrolled in the Mayo Clinic Study of Aging who had baseline MRI. The thickness of selected cortical regions, the volume of white matter hyperintensities, and the frequency of cortical infarctions were compared in participants who were and were not exposed to surgery/GA within 20 yr before the first MRI obtained after enrolment.

RESULTS

Of 1410 participants with MRI scans, 932 were exposed to surgery/GA before scanning. In adjusted analyses, cortical thickness in regions vulnerable to AD was significantly less in those exposed to surgery/GA in the prior 20 yr (difference -0.023 mm, [95% confidence interval (CI) -0.041 to -0.005], P=0.014). Those with surgery in the prior 20 yr were more likely to have 'abnormal thickness' compared with those without surgery (odds ratio=1.45, [95% CI 1.10-1.90], P=0.009). Exposure was not associated with white matter hyperintensities or the presence of brain infarcts.

CONCLUSIONS

This study suggests that exposure of older adults to surgical anaesthesia is associated with thinning in cortical regions implicated in AD. The pathogenesis and mechanisms driving these neurodegenerative changes, and the potential clinical significance of these findings, require further study.

Beyond a rod through the skull: A systematic review of lesion studies of the human ventromedial frontal lobe

Neuropsychological studies from the past century have associated damage to the ventromedial frontal lobes (VMF) with impairments in a variety of domains, including memory, executive function, emotion, social cognition, and valuation. A central question in the literature is whether these seemingly distinct functions are subserved by different sub-regions within the VMF, or whether VMF supports a broader cognitive process that is crucial to these varied domains. In this comprehensive review of the neuropsychological literature from the last two decades, we present a qualitative synthesis of 184 papers that have examined the psychological impairments that result from VMF damage. We discuss these findings in the context of several theoretical frameworks and advocate for the view that VMF is critical for the formation and representation of schema and cognitive maps.

Distinguishing mild cognitive impairment from healthy aging and Alzheimer's Disease: The contribution of the INECO Frontal Screening (IFS)

Executive functions are affected differently in healthy aging, Mild Cognitive Impairment (MCI) and Alzheimer's Disease (AD), and evaluating them is important for differential diagnosis. The INECO Frontal Screening (IFS) is a brief neuropsychological screening tool, developed to assess executive dysfunction in neurodegenerative disorders.

GOALS

We aimed to examine whether and how MCI patients can be differentiated from cognitively healthy controls (HC) and mild to moderate AD patients based on IFS performance. We also explored how IFS scores are associated with age, years of education, and depressive/anxious symptoms (as assessed by the Hospital Anxiety and Depression Scale).

METHOD

IFS total scores were compared between 26 HC, 32 MCI and 21 mild to moderate AD patients. The three groups were matched for age and education. The Area Under the Curve (AUC) was analyzed and optimal cut-offs were determined.

RESULTS

Healthy participants had higher IFS scores than both clinical groups, and MCI patients had higher scores than AD patients. IFS showed high diagnostic accuracy for the detection of MCI (AUC = .89, p < .001) and AD (AUC = .99, p < .001), and for the differentiation between the clinical groups (AUC = .76, p < .001). We provide optimal cut-offs for the identification of MCI and AD and for their differentiation. We also found that, in general, higher education predicted higher IFS scores (no associations with age and depressive/anxious symptoms were observed). Altogether, these findings indicate that evaluating executive functions with the IFS can be valuable for the identification of MCI, a high-risk group for dementia, and for differentiating this condition from healthy aging and AD.

Reduced cortical brain activity with the use of microprocessor-controlled prosthetic knees during walking

BACKGROUND

Individuals using a lower-limb prosthesis indicate that they need to concentrate on every step they take. Despite self-reports of increased cognitive demand, there is limited understanding of the link between cognitive processes and walking when using a lower-limb prosthesis.

OBJECTIVE

The objective was to assess cortical brain activity during level walking in individuals using different prosthetic knee components and compare them to healthy controls. It was hypothesized that the least activity would be observed in the healthy control group, followed by individuals using a microprocessor-controlled prosthetic knee and finally individuals using a non-microprocessor-controlled prosthetic knee.

STUDY DESIGN

Cross-sectional study.

METHODS

An optical brain imaging system was used to measure relative changes in concentration of oxygenated and de-oxygenated haemoglobin in the frontal and motor cortices during level walking. The number of steps and time to walk 10 m was also recorded. The 6-min walk test was assessed as a measure of functional capacity.

RESULTS

Individuals with a transfemoral or knee-disarticulation amputation, using non-microprocessor-controlled prosthetic knee ( n = 14) or microprocessor-controlled prosthetic knee ( n = 15) joints and healthy controls ( n = 16) participated in the study. A significant increase was observed in cortical brain activity of individuals walking with a non-microprocessor-controlled prosthetic knee when compared to healthy controls ( p < 0.05) and individuals walking with an microprocessor-controlled prosthetic knee joint ( p < 0.05).

CONCLUSION

Individuals walking with a non-microprocessor-controlled prosthetic knee demonstrated an increase in cortical brain activity compared to healthy individuals. Use of a microprocessor-controlled prosthetic knee was associated with less cortical brain activity than use of a non-microprocessor-controlled prosthetic knee.

CLINICAL RELEVANCE

Increased understanding of cognitive processes underlying walking when using different types of prosthetic knees can help to optimize selection of prosthetic components and provide an opportunity to enhance functioning with a prosthesis.

Spatial disorientation and executive dysfunction in elderly nondemented patients with Parkinson's disease

OBJECTIVES

Patients with Parkinson's disease (PD) present with a wide range of cognitive deficits. Cognitive impairment is recognized as an independent nonmotor aspect of the disorder and has a critical role in functional outcome and conversion into PD dementia. To date, everyday memory impairment in elderly patients with PD is underinvestigated and its relationship with executive dysfunction was not clearly explained. Our study aims at clarifying the neuropsychological pattern of everyday memory and executive deterioration in elderly patients with PD.

METHODS

Forty nondemented PD patients (mean age 71.2 years; M:F = 29:11) and 30 well-matched controls (mean age 70.7 years; M:F = 15:15) were assessed on everyday memory (Rivermead Behavioral Memory Test [RBMT]) and executive functioning (Frontal Assessment Battery [FAB]) measures. Mann-Whitney U-tests (Bonferroni corrected) were used to compare groups on these measures and Spearman's rank correlations were performed to highlight their associations.

RESULTS

PD patients performed worse than controls on recall for novel tasks and geographic recall (RMBT) as well as lexical fluency and mental flexibility (FAB). Particularly, spatial orientation depending on egocentric navigation seems to be altered in PD patients. The clinical group showed poorer performances than controls in mental flexibility, sensitivity to interference, and inhibitory control. Such measures were associated with immediate and delayed recall, picture recognition, prospective memory, and orientation tasks of everyday memory.

CONCLUSION

Executive-type difficulties and memory-type difficulties have an impact on cognitive performances of elderly patients with PD. We recommend using the RBMT and the FAB as part of routinely neuropsychological battery for assessing PD patients.

Examining neural correlates of psychopathology using a lesion-based approach

Studies of individuals with focal brain damage have long been used to expand understanding of the neural basis of psychopathology. However, most previous studies were conducted using small sample sizes and relatively coarse methods for measuring psychopathology or mapping brain-behavior relationships. Here, we examined the factor structure and neural correlates of psychopathology in 232 individuals with focal brain damage, using their responses to the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF). Factor analysis and voxel-based lesion symptom mapping were used to examine the structure and neural correlates of psychopathology in this sample. Consistent with existing MMPI-2-RF literature, separate internalizing, externalizing, and psychotic symptom dimensions were found. In addition, a somatic dimension likely reflecting neurological symptoms was identified. Damage to the medial temporal lobe, including the hippocampus, was associated with scales related to both internalizing problems and psychoticism. Damage to the medial temporal lobe and orbitofrontal cortex was associated with both a general distrust of others and beliefs that one is being personally targeted by others. These findings provide evidence for the critical role of dysfunction in specific frontal and temporal regions in the development of psychopathology.

Choosing spouses and houses: Impaired congruence between preference and choice following damage to the ventromedial prefrontal cortex

OBJECTIVE

A well-documented effect of focal ventromedial prefrontal cortex (vmPFC) damage is a deficit in real-world decision making. An important aspect of this deficit may be a deficiency in "internal consistency" during social decision making-that is, impaired congruence between expressed preferences versus actual behavioral choices. An example of low internal consistency would be if one expressed the desire to marry someone with impeccable moral character, yet proceeded to marry someone convicted of multiple felonies. Here, we used a neuropsychological approach to investigate neural correlates of internal consistency in complex decision making.

METHOD

Sixteen individuals with focal vmPFC lesions, 16 brain damage comparison individuals, and 16 normal comparison individuals completed a 3-option forced-choice preference task in which choices were made using attribute sets. Participants also completed visual-analogue preference ratings to indicate how much they liked each option, and rated the influence of each attribute on their decision making. Options were either social (potential spouses) or nonsocial (potential houses). Internal consistency for a trial was defined as agreement between the choice and the most positively rated option.

RESULTS

A mixed design analysis of variance revealed that internal consistency between choices and preferences derived from summed attribute ratings was significantly lower for the vmPFC group relative to comparison participants, but only in the social condition (pη2 = .09), 95% CI [.002, .163].

CONCLUSIONS

Internal consistency during social decisions may be deficient in patients with vmPFC damage, leading to a discrepancy between preferences and choices. The vmPFC may provide an important neural mechanism for aligning behavioral choices with expressed preferences. (PsycINFO Database Record

Assessing Executive Dysfunction in Neurodegenerative Disorders: A Critical Review of Brief Neuropsychological Tools

Executive function (EF) has been defined as a multifaceted construct that involves a variety of high-level cognitive abilities such as planning, working memory, mental flexibility, and inhibition. Being able to identify deficits in EF is important for the diagnosis and monitoring of several neurodegenerative disorders, and thus their assessment is a topic of much debate. In particular, there has been a growing interest in the development of neuropsychological screening tools that can potentially provide a reliable quick measure of EF. In this review, we critically discuss the four screening tools of EF currently available in the literature: Executive Interview-25 (EXIT 25), Frontal Assessment Battery (FAB), INECO Frontal Screening (IFS), and FRONTIER Executive Screen (FES). We first describe their features, and then evaluate their psychometric properties, the existing evidence on their neural correlates, and the empirical work that has been conducted in clinical populations. We conclude that the four screening tools generally present appropriate psychometric properties, and are sensitive to impairments in EF in several neurodegenerative conditions. However, more research will be needed mostly with respect to normative data and neural correlates, and to determine the extent to which these tools add specific information to the one provided by global cognition screening tests. More research directly comparing the available tools with each other will also be important to establish in which conditions each of them can be most useful.

Divergent Thinking in Parkinsonism: A Case-Control Study

BACKGROUND

Creativity is a multidimensional phenomenon and an important component of human capacities. This ability is characterized by the involvement of several cognitive functions particularly linked to the prefrontal cortex. We compared divergent thinking, a measure of creativity, in patients affected by progressive supranuclear palsy (PSP), other parkinsonian syndromes, and healthy controls (HCs).

METHODS

Creativity features were evaluated using the Abbreviated Torrance Test for Adults (ATTA). Consecutive PSP outpatients were screened for inclusion. Then, patients with multiple system atrophy (MSA) and Parkinson's disease (PD) and a group of HC were studied. All groups have preserved cognitive functions and were matched for gender, education, disease duration, and age at onset with exception of PD patients who were matched by disease severity rather than disease duration.

RESULTS

PSP patients were characterized by lower values in total ATTA and all subscales than HC and both MSA and PD patients. No differences were found comparing HC versus both MSA and PD patients. PSP patients were characterized by more impaired frontal functioning [assessed by means of Frontal Assessment Battery (FAB)] than HC and both PD and MSA patients.

CONCLUSION

In the present study, ATTA was significantly lower in PSP patients than in the other study groups. The worst performance in ATTA-total score and the lower score in FAB in PSP patients support the role of frontal function in creative processes.

Relationships between risky sexual behaviour, dysexecutive problems, and mental health in the years following interdisciplinary TBI rehabilitation

Little is known about the long-term consequences of traumatic brain injury (TBI) regarding risky sexual behaviour. The objectives of the study were (1) to compare risky sexual behaviour in a sample of individuals with TBI having received interdisciplinary rehabilitation with that of healthy controls, and (2) to explore the relationships between risky sexual behaviour, executive functions, and mental health in individuals with TBI. The study group consisted of 42 individuals with TBI with a mean age of 37.9 years (SD = 9.7), 12.8 years of education (SD = 3.3), and 3.3 years post-injury (SD = 4.3). Healthy controls consisted of 47 participants, with a mean age of 37.6 years (SD = 10.7), and 13 years of education (SD = 3). Risky sexual behaviour was measured with the Sexual Risk Survey and executive function with the Dysexecutive Questionnaire. Mental health measures included the Generalised Anxiety Disorder Scale, and the Patient Health Questionnaire for depression. Compared to healthy controls, individuals with TBI reported more dysexecutive and mental health problems, without differences in risky sexual behaviour. In individuals with TBI, risky sexual behaviour was associated with behavioural, cognitive and emotional dysexecutive problems, but not with anxiety or depression. It was concluded that special attention should be given to individuals with TBI showing difficulties in executive functions given their association with risky sexual behaviour.

Structural Image Analysis of the Brain in Neuropsychology Using Magnetic Resonance Imaging (MRI) Techniques

Magnetic resonance imaging (MRI) of the brain provides exceptional image quality for visualization and neuroanatomical classification of brain structure. A variety of image analysis techniques provide both qualitative as well as quantitative methods to relate brain structure with neuropsychological outcome and are reviewed herein. Of particular importance are more automated methods that permit analysis of a broad spectrum of anatomical measures including volume, thickness and shape. The challenge for neuropsychology is which metric to use, for which disorder and the timing of when image analysis methods are applied to assess brain structure and pathology. A basic overview is provided as to the anatomical and pathoanatomical relations of different MRI sequences in assessing normal and abnormal findings. Some interpretive guidelines are offered including factors related to similarity and symmetry of typical brain development along with size-normalcy features of brain anatomy related to function. The review concludes with a detailed example of various quantitative techniques applied to analyzing brain structure for neuropsychological outcome studies in traumatic brain injury.

You'll change more than I will: Adults' predictions about their own and others' future preferences

It has been argued that adults underestimate the extent to which their preferences will change over time. We sought to determine whether such mispredictions are the result of a difficulty imagining that one's own current and future preferences may differ or whether it also characterizes our predictions about the future preferences of others. We used a perspective-taking task in which we asked young people how much they liked stereotypically young-person items (e.g., Top 40 music, adventure vacations) and stereotypically old-person items (e.g., jazz, playing bridge) now, and how much they would like them in the distant future (i.e., when they are 70 years old). Participants also made these same predictions for a generic same-age, same-sex peer. In a third condition, participants predicted how much a generic older (i.e., age 70) same-sex adult would like items from both categories today. Participants predicted less change between their own current and future preferences than between the current and future preferences of a peer. However, participants estimated that, compared to a current older adult today, their peer would like stereotypically young items more in the future and stereotypically old items less. The fact that peers' distant-future estimated preferences were different from the ones they made for "current" older adults suggests that even though underestimation of change of preferences over time is attenuated when thinking about others, a bias still exists.

Diversity of approaches in assessment of executive functions in stroke: limited evidence?

Stroke is a leading cause of disability worldwide. Cognitive functions and, in particular, executive function, are commonly affected after stroke, leading to impairments in performance of daily activities, decrease in social participation and in quality of life. Appropriate assessment and understanding of executive dysfunction are important, firstly to develop better rehabilitation strategies for executive functions per se and secondly to consider executive function abilities on rehabilitation strategies in general. The purpose of this review was to identify the most widely used assessment tools of executive dysfunction for patients with stroke, and their psychometric properties.

We systematically reviewed manuscripts published in English in databases from 1999 to 2015. We identified 35 publications. The most frequently used instruments were the Stroop, Digit Span and Trail making tests. Psychometric properties were described for the Executive Function Performance Test, Executive Clock Drawing Task, Chinese Frontal Assessment Battery and Virtual Action Planning — Supermarket, and two subtests of the Cambridge Cognitive Examination — Revised.

There is a paucity of tools to reliably measure executive dysfunction after stroke, despite the fact that executive dysfunction is frequent. Identification of the best tools for executive dysfunction assessment is necessary to address important gaps in research and in clinical practice.

Neural correlates of visual hallucinations in dementia with Lewy bodies

INTRODUCTION

The aim of this study was to investigate the association between visual hallucinations in dementia with Lewy bodies (DLB) and brain perfusion using single-photon emission computed tomography.

METHODS

We retrospectively included 66 patients with DLB, 36 of whom were having visual hallucinations (DLB-hallu) and 30 of whom were not (DLB-c). We assessed visual hallucination severity on a 3-point scale of increasing severity: illusions, simple visual hallucinations and complex visual hallucinations. We performed voxel-level comparisons between the two groups and assessed correlations between perfusion and visual hallucinations severity.

RESULTS

We found a significant decrease in perfusion in the left anterior cingulate cortex, the left orbitofrontal cortex and the left cuneus in the DLB-hallu group compared with the DLB-c group. We also found a significant correlation between decreased bilateral anterior cingulate cortex, left orbitofrontal cortex, right parahippocampal gyrus, right inferior temporal cortex and left cuneus perfusion with the severity of hallucinations.

CONCLUSIONS

Visual hallucinations seem to be associated with the impairment of anterior and posterior regions (secondary visual areas, orbitofrontal cortex and anterior cingulate cortex) involved in a top-down and bottom-up mechanism, respectively. Furthermore, involvement of the bilateral anterior cingulate cortex and right parahippocampal gyrus seems to lead to more complex hallucinations.

Impaired self-awareness in human addiction: deficient attribution of personal relevance

Compromised self-awareness of illness-related deficits and behaviors in psychopathology (e.g., schizophrenia) has been associated with deficient functioning of cortical midline regions including the ventromedial prefrontal cortex (vmPFC), implicated in personal relevance. Here, we review and critically analyze recent evidence to suggest that vmPFC abnormalities could similarly underlie deficient tagging of personal relevance in drug addiction, evidenced by a constellation of behaviors encompassing drug-biased attention, negative outcome insensitivity, self-report/behavior dissociation, and social inappropriateness. This novel framework might clarify, for example, why drug-addicted individuals often ruin long-standing relationships or forego important job opportunities while continuing to engage in uncontrolled drug-taking. Therapeutic interventions targeting personal relevance and associated vmPFC functioning could enhance self-awareness and facilitate more adaptive behavior in this chronically relapsing psychopathology.

Task-dependent recruitment of intrinsic brain networks reflects normative variance in cognition

BACKGROUND

Functional neuroimaging has great potential to inform clinical decisions, whether by identifying neural biomarkers of illness progression and severity, predicting therapeutic response, or selecting suitable patients for surgical interventions. Yet a persisting barrier to functional neuroimaging's clinical translation is our incomplete understanding of how normative variance in cognition, personality, and behavior shape the brain's structural and functional organization. We propose that modeling individual differences in these brain-behavior relationships is crucial for improving the accuracy of neuroimaging biomarkers for neurologic and psychiatric disorders.

METHODS

We addressed this goal by initiating the Cognitive Connectome Project, which bridges neuropsychology and neuroimaging by pairing nine cognitive domains typically assessed by clinically validated neuropsychological measures with those tapped by canonical neuroimaging tasks (motor, visuospatial perception, attention, language, memory, affective processing, decision making, working memory, and executive function). To date, we have recruited a diverse sample of 53 participants (mean [SD], age = 32 [9.7] years, 31 females).

RESULTS

As a proof of concept, we first demonstrate that our neuroimaging task battery can replicate previous findings that task performance recruits intrinsic brain networks identified during wakeful rest. We then expand upon these previous findings by showing that the extent to which these networks are recruited by task reflects individual differences in cognitive ability. Specifically, performance on the Judgment of Line Orientation task (a clinically validated measure of visuospatial perception) administered outside of the MRI scanner predicts the magnitude of task-induced activity of the dorsal visual network when performing a direct replication of this task within the MRI scanner. Other networks (such as default mode and right frontoparietal) showed task-induced changes in activity that were unrelated to task performance, suggesting these networks to not be involved in visuospatial perception.

CONCLUSION

These findings establish a methodological framework by which clinical neuropsychology and functional neuroimaging may mutually inform one another, thus enhancing the translation of functional neuroimaging into clinical decision making.

Ecological validity and neuroanatomical correlates of the NIH EXAMINER executive composite score

Executive functions refer to a constellation of higher-level cognitive abilities that enable goal-oriented behavior. The NIH EXAMINER battery was designed to assess executive functions comprehensively and efficiently. Performance can be summarized by a single score, the "Executive Composite," which combines measures of inhibition, set-shifting, fluency, and working memory. We evaluated the ecological validity of the Executive Composite in a sample of 225 mixed neurological patients and controls using the Frontal Systems Behavior Scale (FrSBe), an informant-based measure of real-world executive behavior. In addition, we investigated the neuroanatomical correlates of the Executive Composite using voxel-based morphometry in a sample of 37 participants diagnosed with dementia, mild cognitive impairment, or as neurologically healthy. The Executive Composite accounted for 28% of the variance in Frontal Systems Behavior Scale scores beyond age. Even after including two widely used executive function tests (Trails B and Stroop) as covariates, the Executive Composite remained a significant predictor of real-world behavior. Anatomically, poorer scores on the Executive Composite were associated with smaller right and left dorsolateral prefrontal volumes, brain regions critical for good executive control. Taken together, these results suggest that the Executive Composite measures important aspects of executive function not captured by standard measures and reflects the integrity of frontal systems.