Measures Of Executive Function Research Articles

Assessing the Contribution of Measures of Attention and Executive Function to Diagnosis of ADHD or Autism.

Attention and executive function (EF) dysregulation are common in a number of disorders including autism and attention-deficit/hyperactivity disorder (ADHD). Better understanding of the relationship between indirect and direct measures of attention and EF and common neurodevelopmental diagnoses may contribute to more efficient and effective diagnostic assessment in childhood. We obtained cognitive (NIH Toolbox, Little Man Task, Matrix Reasoning Task, and Rey Delayed Recall) and symptom (CBCL, and BPMT) assessment data from the Adolescent Brain and Cognitive Development (ABCD) database for three groups, autistic (N = 110), ADHD (N = 878), and control without autism or ADHD diagnoses (N = 9130) and used ridge regression to determine which attention and EF assessments were most strongly associated with autism or ADHD. More variance was accounted for in the model for the ADHD group (31%) compared to the autism group (2.7%). Finally, we ran odds ratios (using clinical cutoffs where available and 2 standard deviations below the mean when not) for each assessment measure, which generally demonstrated a greater significance within the indirect measures when compared to the direct measures. These results add to the growing literature of symptom variably across diagnostic groups allowing for better understanding of presentations in autism and ADHD and how best to assess diagnosis. It also highlights the increased difficulty in differentiating autism and controls when compared to ADHD and controls and the importance of indirect measures of attention and EF in this differentiation.

Six elements test vs D-KEFS: what does "Ecological Validity" tell us?

Extensive research shows that tests of executive functioning (EF) predict instrumental activities of daily living (IADLs) but are nevertheless often criticized for having poor ecological validity. The Modified Six Elements Test (MSET) is a pencil-and-paper test that was developed to mimic the demands of daily life, with the assumption that this would result in a more ecologically valid test. Although the MSET has been extensively validated in its ability to capture cognitive deficits in various populations, support for its ability to predict functioning in daily life is mixed. This study aimed to examine the MSET's ability to predict IADLs assessed via three different modalities relative to traditional EF measures. Participants (93 adults aged 60 - 85) completed the MSET, traditional measures of EF (Delis-Kaplan Executive Function System; D-KEFS), and self-reported and performance-based IADLs in the lab. Participants then completed three weeks of IADL tasks at home, using the Daily Assessment of Independent Living and Executive Skills (DAILIES) protocol. The MSET predicted only IADLs completed at home, while the D-KEFS predicted IADLs across all three modalities. Further, the D-KEFS predicted home-based IADLs beyond the MSET when pitted against each other, whereas the MSET did not contribute beyond the D-KEFS. Traditional EF tests (D-KEFS) appear to be superior to the MSET in predicting IADLs in community-dwelling older adults. The present results argue against replacing traditional measures with the MSET when addressing functional independence of generally high-functioning and cognitive healthy older adult patients.

Executive function and decision-making in Colombian patients with paranoid schizophrenia

Background Schizophrenia (SCZD) is a mental disorder characterized by cognitive dysfunction, impaired decision-making abilities, abnormalities in brain functioning, and specific genetic markers. Ethnic and racial factors influence the development and presentation of schizophrenia, with different groups experiencing different levels of risk and exhibiting different patterns of mental disorders. Objective We sought to investigate the executive function and decision-making profile of Schizophrenia participants from Barranquilla, Colombia, which have a high genetic mixture and significant ethnic and racial diversity. Methods The sample consists of 40 individuals, 20 diagnosed with paranoid schizophrenia and 20 controls. We use the BANFE neuropsychological battery and the Iowa Gambling task to measure executive function and decision-making processes. Results The study found differences in cognitive performance, measured by the Neuropsychological Battery of Executive Functions and Frontal Lobes, in the medial orbit, anterior prefrontal, dorsolateral, and total executive function measures. In decision-making, as measured by the Iowa Gambling Test, there were also differences between the two groups, with those with schizophrenia performing worse and showing a preference for disadvantageous options. The study also found that there were no significant differences in socio-demographic characteristics between the two groups but that there were differences in terms of socio-economic status and educational level. Conclusion This study found that individuals with paranoid schizophrenia had significant differences in their prefrontal cortex compared to those without the condition, specifically in the dorsolateral and orbital-prefrontal cortex. These differences may be linked to difficulties adjusting to their environment and processing reinforcement, leading to impaired learning and arousal disturbances.

Effect of Pre-Training and Role of Working Memory Characteristics in Learning with Immersive Virtual Reality

Immersive virtual reality (IVR) is being incorporated into education, but not all learners have expertise in using this technology. As such, this research examined whether pre-training in IVR can reduce the novelty of this technology and enhance learning from IVR lessons and understand the role of individual differences in managing incoming information (i.e., executive function) and capacity for holding information (i.e., working memory capacity) in learning from an IVR lesson. Participants were split into two conditions; half of the participants played a game in IVR to become knowledgeable about IVR technology and the other half did not play this game. All participants then learned a lesson in IVR, took a posttest, and completed working memory tasks. The results showed that playing the game prior to learning in IVR did not change the learners’ experience of distraction or their learning outcome, indicating that IVR game-playing was not an effective form of pre-training. Additionally, several measures of executive function and working memory capacity were correlated with posttest performance, indicating that students with better executive function learn better with distracting media such as IVR, regardless of pre-training. Theoretical and practical implications are discussed.

Four weeks of meditation training improves sustained attention in community-dwelling older adults: a proof-of-concept randomized controlled trial.

Introduction: With our rapidly expanding population of older adults, identifying effective intervention strategies to improve cognitive functioning is an increasing priority. This study sought to examine whether 4weeks of thrice-weekly meditation training can improve attention in older adults, as well as whether such benefits may extend to other domains of cognition as well as mobility. Methods: Forty-three participants (mean age 68years) were randomized into either the focused attention meditation group or the music listening control group (Clinicaltrials.gov ID NCT03417635). Participants completed three 20-minute guided group sessions per week for four consecutive weeks. Our primary outcome measure was behavioural performance on the Sustained Attention to Response Task (SART). Secondary and tertiary outcome measures included event-related potentials (ERPs) during the SART task, measures of executive functioning, and measures of mobility. Results: We found that meditation training significantly improved attention, as demonstrated by improved SART accuracy and changes in N2 ERP amplitude and latency. Discussion: These findings suggest that meditation may lead to changes in attention and underlying cognitive processing in older adults, although a full-scale definitive trial is needed. Future research on the long-term benefits with real world applications is warranted.

Airborne Lead Exposure and Childhood Cognition: The Environmental Influences on Child Health Outcomes (ECHO) Cohort (2003-2022).

Objectives. To examine whether a previously reported association between airborne lead exposure and children's cognitive function replicates across a geographically diverse sample of the United States. Methods. Residential addresses of children (< 5 years) were spatially joined to the Risk-Screening Environmental Indicators model of relative airborne lead toxicity. Cognitive outcomes for children younger than 8 years were available for 1629 children with IQ data and 1476 with measures of executive function (EF; inhibitory control, cognitive flexibility). We used generalized linear models using generalized estimating equations to examine the associations of lead, scaled by interquartile range (IQR), accounting for individual- and area-level confounders. Results. An IQR increase in airborne lead was associated with a 0.74-point lower mean IQ score (b = -0.74; 95% confidence interval = -1.00, -0.48). The association between lead and EF was nonlinear and was modeled with a knot at the 97.5th percentile of lead in our sample. Lead was significantly associated with lower mean inhibitory control but not with cognitive flexibility. This effect was stronger among males for both IQ and inhibitory control. Conclusions. Early-life exposure to airborne lead is associated with lower cognitive functioning. (Am J Public Health. 2024;114(3):309-318. https://doi.org/10.2105/AJPH.2023.307519).

Robust reference group normative data for neuropsychological tests accounting for primary language use in Asian American older adults.

The present study aimed to develop neuropsychological norms for older Asian Americans with English as a primary or secondary language, using data from the National Alzheimer's Coordinating Center (NACC). A normative sample of Asian American participants was derived from the NACC database using robust criteria: participants were cognitively unimpaired at baseline (i.e., no MCI or dementia) and remained cognitively unimpaired at 1-year follow-up. Clinical and demographic characteristics were compared between Primary and Secondary English speakers using analyses of variance for continuous measures and chi-square tests for categorical variables. Linear regression models compared neuropsychological performance between the groups, adjusting for demographics (age, sex, and education). Regression models were developed for clinical application to compute demographically adjusted z-scores. Secondary English speakers were younger than Primary English speakers (p < .001). There were significant differences between the groups on measures of mental status (Mini-Mental State Examination, p = .002), attention (Trail Making Test A, Digit Span Forward Total Score, p <.001), language (Boston Naming Test, Animal Fluency, Vegetable Fluency, p < .001), and executive function (Trail Making Test B, p = .02). Separate normative data are needed for Primary vs. Secondary English speakers from Asian American backgrounds. We provide normative data on older Asian Americans to enable clinicians to account for English use in the interpretation of neuropsychological assessment scores.

Resting EEG Periodic and Aperiodic Components Predict Cognitive Decline Over 10 Years.

Measures of intrinsic brain function at rest show promise as predictors of cognitive decline in humans, including EEG metrics such as individual α peak frequency (IAPF) and the aperiodic exponent, reflecting the strongest frequency of α oscillations and the relative balance of excitatory/inhibitory neural activity, respectively. Both IAPF and the aperiodic exponent decrease with age and have been associated with worse executive function and working memory. However, few studies have jointly examined their associations with cognitive function, and none have examined their association with longitudinal cognitive decline rather than cross-sectional impairment. In a preregistered secondary analysis of data from the longitudinal Midlife in the United States (MIDUS) study, we tested whether IAPF and aperiodic exponent measured at rest predict cognitive function (N = 235; age at EEG recording M = 55.10, SD = 10.71) over 10 years. The IAPF and the aperiodic exponent interacted to predict decline in overall cognitive ability, even after controlling for age, sex, education, and lag between data collection time points. Post hoc tests showed that "mismatched" IAPF and aperiodic exponents (e.g., higher exponent with lower IAPF) predicted greater cognitive decline compared to "matching" IAPF and aperiodic exponents (e.g., higher exponent with higher IAPF; lower IAPF with lower aperiodic exponent). These effects were largely driven by measures of executive function. Our findings provide the first evidence that IAPF and the aperiodic exponent are joint predictors of cognitive decline from midlife into old age and thus may offer a useful clinical tool for predicting cognitive risk in aging.

The common factor of executive functions measures nothing but speed of information uptake

There is an ongoing debate about the unity and diversity of executive functions and their relationship with other cognitive abilities such as processing speed, working memory capacity, and intelligence. Specifically, the initially proposed unity and diversity of executive functions is challenged by discussions about (1) the factorial structure of executive functions and (2) unfavorable psychometric properties of measures of executive functions. The present study addressed two methodological limitations of previous work that may explain conflicting results: The inconsistent use of (a) accuracy-based vs. reaction time-based indicators and (b) average performance vs. difference scores. In a sample of 148 participants who completed a battery of executive function tasks, we tried to replicate the three-factor model of the three commonly distinguished executive functions shifting, updating, and inhibition by adopting data-analytical choices of previous work. After addressing the identified methodological limitations using drift–diffusion modeling, we only found one common factor of executive functions that was fully accounted for by individual differences in the speed of information uptake. No variance specific to executive functions remained. Our results suggest that individual differences common to all executive function tasks measure nothing more than individual differences in the speed of information uptake. We therefore suggest refraining from using typical executive function tasks to study substantial research questions, as these tasks are not valid for measuring individual differences in executive functions.

Exploring symptom clusters in mild cognitive impairment and dementia with the NIH Toolbox.

Symptom clustering research provides a unique opportunity for understanding complex medical conditions. The objective of this study was to apply a variable-centered analytic approach to understand how symptoms may cluster together, within and across domains of functioning in mild cognitive impairment (MCI) and dementia, to better understand these conditions and potential etiological, prevention, and intervention considerations. Cognitive, motor, sensory, emotional, and social measures from the NIH Toolbox were analyzed using exploratory factor analysis (EFA) from a dataset of 165 individuals with a research diagnosis of either amnestic MCI or dementia of the Alzheimer's type. The six-factor EFA solution described here primarily replicated the intended structure of the NIH Toolbox with a few deviations, notably sensory and motor scores loading onto factors with measures of cognition, emotional, and social health. These findings suggest the presence of cross-domain symptom clusters in these populations. In particular, negative affect, stress, loneliness, and pain formed one unique symptom cluster that bridged the NIH Toolbox domains of physical, social, and emotional health. Olfaction and dexterity formed a second unique cluster with measures of executive functioning, working memory, episodic memory, and processing speed. A third novel cluster was detected for mobility, strength, and vision, which was considered to reflect a physical functioning factor. Somewhat unexpectedly, the hearing test included did not load strongly onto any factor. This research presents a preliminary effort to detect symptom clusters in amnestic MCI and dementia using an existing dataset of outcome measures from the NIH Toolbox.

Executive Functioning and Offending Behavior: An Updated Meta-Analysis

Executive (dys)functioning is a known risk factor for offending behavior. A meta-analysis was conducted to understand differences in executive functioning across justice-involved and non-justice-involved groups. Across 37 studies, justice-involved groups performed significantly worse on measures of executive functioning compared with controls, with a random-effects grand mean effect size of Cohen’s d = 0.55. However, 84.8% of the variance in effect size was due to between-study heterogeneity. Subgroup analyses and meta-regression were conducted to examine differences across age group (adult vs. adolescent), the measure of executive functioning, and intelligence quotient (IQ). Age group was a significant moderator such that there was a significant overall random-effects effect size for adults (Cohen’s d = 0.72) but not for adolescents (Cohen’s d = 0.18). The type of executive functioning measure and IQ were non-significant in random-effects models. Results indicate that, for adults, a robust difference in executive functioning performance exists between justice-involved and non-justice-involved groups. Clinical and correctional policy implications are discussed within the Risk-Needs-Responsivity framework.

Neural and Cognitive Predictors of Stimulant Treatment Efficacy in Medication-Naïve ADHD Adults: A Pilot Diffusion Tensor Imaging Study

Objective: Stimulant medications are the main treatment for Attention Deficit Hyperactivity Disorder (ADHD), but overall treatment efficacy in adults has less than a 60% response rate. This study aimed to identify neural and cognitive markers predictive of longitudinal improvement in response to stimulant treatment in drug-naïve adults with ADHD. Method: We used diffusion tensor imaging (DTI) and executive function measures with 36 drug-naïve adult ADHD patients in a prospective study design. Results: Structural connectivity (measured by fractional anisotropy, FA) in striatal regions correlated with ADHD clinical symptom improvement following stimulant treatment (amphetamine or methylphenidate) in better medication responders. A significant positive correlation was also found between working memory performance and stimulant-related symptom improvement. Higher pre-treatment working memory scores correlated with greater response. Conclusion: These findings provide evidence of pre-treatment neural and behavioral markers predictive of longitudinal treatment response to stimulant medications in adults with ADHD.

Cognitive and psychological dysfunction is present after a first seizure, prior to epilepsy diagnosis and treatment at a First Seizure Clinic.

Neuropsychological comorbidities found in chronic epilepsy have also been reported earlier in the disease course. However, recurrent seizures, antiseizure medication (ASM), and adjustment to a chronic diagnosis remain potential confounds of this literature. It thus remains unclear whether these comorbidities are primary or secondary attributes of epilepsy. To capture individuals as close to disease onset as possible, we studied the cognitive and psychological functioning in adults after their first seizure, yet prior to epilepsy diagnosis and treatment. Using a telehealth-based prospective design, we screened cognition, mood, and anxiety symptoms in adult patients referred to a First Seizure Clinic (FSC), who were over 18 years, English-speaking and not taking ASM. We screened cognition via telephone, and psychological symptoms via online questionnaires, all prior to the patients' diagnostic evaluation. Data were collected on 32 individuals subsequently diagnosed with epilepsy at the FSC, and 30 healthy controls from the community, who were matched to the epilepsy group for age, gender, and education. A multivariate analysis of variance revealed that the groups differed significantly on combined cognitive measures with a large effect size (F[1,56] = 5.75, p < 0.001, η2 = 0.45). Post-hoc analyses showed that performances on measures of verbal memory, working memory, and executive functions were significantly worse for the newly diagnosed epilepsy group than controls. The epilepsy group also exhibited higher rates of clinically significant depressive and anxiety symptoms. Cognitive and psychological dysfunction is prevalent in people with epilepsy as early as the first seizure event, before the influence of diagnosis, ASM and recurrent seizures. Their neuropsychological profile parallels that seen in chronic epilepsy, showing that this dysfunction is already present at the very onset of the disease. The current study demonstrates the viability of telehealth neuropsychological screening for all new epilepsy cases. The results of this study show, using telephone-based cognitive assessment and online questionnaires, that people with newly diagnosed epilepsy can experience problems with their thinking and memory skills, and low mood and anxiety, as early as after their first seizure. These issues are apparent at the very beginning of the disease, before an epilepsy diagnosis is made and before antiseizure medication is commenced, which suggests that they are due to the underlying brain disturbance, rather than the secondary effects of seizures, treatment, or lifestyle changes. Telehealth-screening of thinking skills and mental health for all new epilepsy cases is recommended to promote early management of such problems.

Investigating executive functioning and episodic future thinking in Iranian women with breast cancer

Background This study examined executive functioning and episodic future thinking among Iranian women with breast cancer. Method We recruited 40 healthy female community volunteers and 80 females with breast cancer (either currently undergoing chemotherapy n = 40 or not undergoing chemotherapy n = 40). Participants were assessed using cognitive tasks that assessed executive functioning and episodic future thinking and a measure of cancer-related fatigue. Results Both cancer groups had poorer performance than controls on all measures of executive functioning and episodic future thinking. Those undergoing chemotherapy had poorer performance on all measures of executive functioning than those not undergoing chemotherapy. Cross-sectional mediation analyses revealed cancer-related fatigue had a significant mediator role between cancer group and executive functioning and episodic future thinking. Conclusion Those with breast cancer, particularly those undergoing chemotherapy, may be experiencing cognitive difficulties. These cognitive concerns should be considered by health teams as addressing these impairments may assist in improving quality of life and treatment adherence.

Executive functions assessment in very preterm children at school age: A pilot study about a clinical and experimental approach

While the survival rate of very preterm (VPT) infants has increased in the last decades, they are still at risk of developing long-term neurodevelopmental impairments, especially regarding self-regulatory abilities, and goal-directed behaviors. These skills rely on executive functions (EFs), an umbrella term encompassing the core capacities for inhibition, shifting, and working memory. Existing comprehensive tests are time-consuming and therefore not suitable for all pediatric neuropsychological assessments. The Flanker task is an experimental computer game having the advantage to last less than ten minutes while giving multiple EFs measures. Here, we tested the potency of this task in thirty-one VPT children aged 8–10 years during their clinical assessment. First, we found that VPT children performed in the norm for most clinical tests (i.e., WISC-V, BRIEF, and NEPSY) except for the CPT-3 where they were slower with more omission errors, which could indicate inattentiveness. Second, some Flanker task scores were correlated with standardized clinical testing without resisting to multiple comparisons correction. Finally, compared to full-term children, VPT children showed poorer performance in global EFs measure and lower accuracy in the Flanker task. These findings suggest that this child-friendly version of the Flanker task demonstrated a reasonable sensitivity in capturing EFs with good discrimination between VPT and term children despite VPT children’s mild difficulties. It may represent a promising tool for neuropsychological assessments and be suitable as a screening test, providing further validating larger studies. Moreover, while VPT schoolchildren globally display normal intelligence, subtle difficulties that seem to relate to EFs are observed.

Measures of executive function may not be indicators of latent constructs.

Executive function (EF) is represented by a multidimensional set of measures. The central EFs considered are inhibitory control, working memory and cognitive flexibility (task shifting). Unlike other ability constructs, it has proven difficult to identify latent factors that underlie EF. Research has often taken a factor analytic approach for grouping executive functioning tasks. However, this approach has often proven unsuccessful. We aimed to compare factor analysis to a network analytic approach, as network analysis can summarize the pattern of relationships among elements without creating latent constructs. One hundred and thirteen undergraduate students completed a series of nine executive functioning tasks. In comparing exploratory factor analysis to network analysis, we found neither approach provided a compelling higher order grouping of EF measures.

Distinguishing between Iranian adolescents with posttraumatic stress disorder and high and low depressive symptoms: The role of cognitive and emotional variables.

This study aimed to investigate the role of cognitive and emotional variables in distinguishing between adolescents with posttraumatic stress disorder (PTSD) and either low or high symptoms of depression. Adolescents (N = 90) aged between 13 and 17 years (Mage = 15.53, SD = 1.13) who had been exposed to an earthquake in Iran and had (a) not developed PTSD (n = 30), (b) developed PTSD with low symptoms of depression (n = 30), and (c) developed PTSD with high symptoms of depression (n = 30) completed a clinical interview, cognitive tasks, and the Cognitive Emotion Regulation Questionnaire. We found that those with PTSD had poorer performance on executive functioning (inhibition, cognitive flexibility, and working memory), episodic future thinking, and attention bias and had greater maladaptive emotion regulation strategies than healthy controls. Among those with PTSD, adolescents with high symptoms of depression performed worse on measures of executive function, attention bias, episodic future thinking, and the emotion regulation strategies of rumination and catastrophizing than adolescents with low depressive symptoms. Exploring these cognitive and emotion difficulties can assist in further understanding PTSD and depression and improve targeted interventions among adolescents. This is of particular relevance in Iran where the need for policies and interventions targeting PTSD has been identified. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Carotid Revascularization is Associated with Improved Mood in Patients with Advanced Carotid Disease.

To investigate the impact of carotid interventions on patients' mental condition in patients with carotid stenosis. Ongoing research highlights the impact of carotid interventions on neurocognitive function in patients with advanced carotid atherosclerosis. However, data regarding the impact of carotid revascularization on mood is scarce. A total of 157 patients undergoing carotid revascularization were prospectively recruited. The primary outcome was depression, evaluated pre-operatively, and at 1-,6- and 12-month post-intervention using the long form of the geriatric depression scale (GDS-30) questionnaire. Other tests were also used to assess cognition at the respective timepoints. Statistical analyses were performed to assess the postoperative outcomes compared to baseline. Baseline depression (GDS>9) was observed in 49(31%) subjects, whereas 108(69%) patients were not depressed (GDS≤9). The average pre-operative GDS score was 15.42 ± 4.40(14.2-16.7) and 4.28 ±2.9(3.7-4.8) in the depressed and non-depressed groups, respectively. We observed a significant improvement in GDS scores within the depressed group at 1-month (P=0.002), 6-months (P=0.027), and 1-year (P<0.001) post-intervention compared to preop, whereas the non-depressed group had similar post-op GDS scores at all time points compared to baseline. Significant improvement in measures of executive function was seen in non-depressed patients at all three timepoints whereas depressed patients showed an improvement at 1-year follow-up. Our study highlights improvement in mood among patients with advanced carotid disease who screened positive for depression at baseline. Further studies with larger sample sizes are warranted to investigate the association between depression, carotid disease, and carotid intervention.

Neurocognitive and psychosocial outcomes in survivors of childhood leukemia with Down syndrome.

The primary aim of this study was to assess the feasibility of a developmentally tailored neurocognitive assessment in survivors of childhood acute leukemia with Down syndrome (DS-leukemia). A secondary aim was to compare outcomes in the DS-leukemia group to a historical comparison group of individuals with DS and no history of childhood cancer. Survivors of DS-leukemia (n = 43; 56% male, mean [SD] age at diagnosis = 4.3 [4.5] years; age at evaluation = 15 [7.9] years) completed a neurocognitive assessment battery that included direct measures of attention, executive function, and processing speed, and proxy ratings of attention problems and executive dysfunction. Direct assessment outcomes were compared to a historical comparison cohort of individuals with DS and no history of childhood cancer (DS-control; n = 117; 56% male, mean [SD] age at evaluation = 12.7 [3.4] years). Rates of valid task completion ranged from 54% to 95%, suggesting feasibility for most direct assessment measures. Compared to the DS-control group, the DS-leukemia group had significantly lower completion rates on measures of executive function (p = 0.008) and processing speed (p = 0.018) compared to the DS-control group. There were no other significant group differences in completion rates. Compared to the DS-control group, the DS-leukemia group had significantly more accurate performance on two measures of executive function (p = 0.032; p = 0.005). Compared to the DS-control group, the DS-leukemia group had significantly more problems with executive function as identified on proxy ratings (6.5% vs. 32.6%, p = <0.001). Children with Down syndrome (DS) are at increased risk for developing acute leukemia compared to the general population but are systematically excluded from neurocognitive outcome studies among leukemia survivors. This study demonstrated the feasibility of evaluating neurocognitive late effects in leukemia survivors with DS using novel measures appropriate for populations with intellectual developmental disorder.

More Similar than Different: Memory, Executive Functions, Cortical Thickness, and Glucose Metabolism in Biomarker-Positive Alzheimer's Disease and Behavioral Variant Frontotemporal Dementia.

Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) are typically associated with very different clinical and neuroanatomical presentations; however, there is increasing recognition of similarities. To examine memory and executive functions, as well as cortical thickness, and glucose metabolism in AD and bvFTD signature brain regions. We compared differences in a group of biomarker-defined participants with Alzheimer's disease and a group of clinically diagnosed participants with bvFTD. These groups were also contrasted with healthy controls (HC). As expected, memory functions were generally more impaired in AD, followed by bvFTD, and both clinical groups performed more poorly than the HC group. Executive function measures were similar in AD compared to bvFTD for motor sequencing and go/no-go, but bvFTD had more difficulty with a set shifting task. Participants with AD showed thinner cortex and lower glucose metabolism in the angular gyrus compared to bvFTD. Participants with bvFTD had thinner cortex in the insula and temporal pole relative to AD and healthy controls, but otherwise the two clinical groups were similar for other frontal and temporal signature regions. Overall, the results of this study highlight more similarities than differences between AD and bvFTD in terms of cognitive functions, cortical thickness, and glucose metabolism. Further research is needed to better understand the mechanisms mediating this overlap and how these relationships evolve longitudinally.