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Social cognition is impaired in mild cognitive impairment (MCI) and dementia. However, its relationship to social functioning and perceived social support has yet to be explored. Here, we examine how theory of mind (ToM) relates to social functioning in MCI and dementia.
Methods:
Older adults (cognitively normal = 1272; MCI = 132; dementia = 23) from the PATH Through Life project, a longitudinal, population-based study, were assessed on the Reading the Mind in the Eyes Test (RMET), measures of social functioning, and social well-being. The associations between RMET performance, social functioning, and cognitive status were analysed using generalised linear models, adjusting for demographic variables.
Results:
Participants with MCI (b=−.52, 95% CI [−.70, −.33]) and dementia (b=−.78, 95% CI [−1.22, −.34]) showed poorer RMET performance than cognitively normal participants. Participants with MCI and dementia reported reduced social network size (b=−.21, 95% CI [−.40, −.02] and b=−.90, 95% CI [−1.38, −.42], respectively) and participants with dementia reported increased loneliness (b = .36, 95% CI [.06, .67]). In dementia, poorer RMET performance was associated with increased loneliness (b=−.07, 95% CI [−.14, −.00]) and a trend for negative interactions with partners (b=−.37, 95% CI [−.74, .00]), but no significant associations were found in MCI.
Conclusions:
MCI and dementia were associated with poor self-reported social function. ToM deficits were related to poor social function in dementia but not MCI. Findings highlight the importance of interventions to address social cognitive deficits in persons with dementia and education of support networks to facilitate positive interactions and social well-being.
Subjective Cognitive Decline (SCD) may be an early indicator of risk for Alzheimer’s disease (AD). Findings regarding sex differences in SCD are inconsistent. Studying sex differences in SCD within cognitively unimpaired individuals with autosomal-dominant AD (ADAD), who will develop dementia, may inform sex-related SCD variations in preclinical AD. We examined sex differences in SCD within cognitively unimpaired mutation carriers from the world’s largest ADAD kindred and sex differences in the relationship between SCD and memory performance.
Methods:
We included 310 cognitively unimpaired Presenilin-1 (PSEN-1) E280A mutation carriers (51% females) and 1998 noncarrier family members (56% females) in the study. Subjects and their study partners completed SCD questionnaires and the CERAD word list delayed recall test. ANCOVAs were conducted to examine group differences in SCD, sex, and memory performance. In carriers, partial correlations were used to examine associations between SCD and memory performance covarying for education.
Results:
Females in both groups had greater self-reported and study partner-reported SCD than males (all p < 0.001). In female mutation carriers, greater self-reported (p = 0.02) and study partner-reported SCD (p < 0.001) were associated with worse verbal memory. In male mutation carriers, greater self-reported (p = 0.03), but not study partner-reported SCD (p = 0.11) was associated with worse verbal memory.
Conclusions:
Study partner-reported SCD may be a stronger indicator of memory decline in females versus males in individuals at risk for developing dementia. Future studies with independent samples and preclinical trials should consider sex differences when recruiting based on SCD criteria.
To identify novel associations between modifiable physical and health variables, Alzheimer’s disease (AD) biomarkers, and cognitive function in a cohort of older adults with Mild Cognitive Impairment (MCI).
Methods:
Metrics of cardiometabolic risk, stress, inflammation, neurotrophic/growth factors, AD, and cognition were assessed in 154 MCI participants (Mean age = 74.1 years) from the Alzheimer’s Disease Neuroimaging Initiative. Partial Least Squares analysis was employed to examine associations among these physiological variables and cognition.
Results:
Latent variable 1 revealed a unique combination of AD biomarkers, neurotrophic/growth factors, education, and stress that were significantly associated with specific domains of cognitive function, including episodic memory, executive function, processing speed, and language, representing 45.2% of the cross-block covariance in the data. Age, body mass index, and metrics tapping basic attention or premorbid IQ were not significant.
Conclusions:
Our data-driven analysis highlights the significant relationships between metrics associated with AD pathology, neuroprotection, and neuroplasticity, primarily with tasks tapping episodic memory, executive function, processing speed, and verbal fluency rather than more basic tasks that do not require mental manipulation (basic attention and vocabulary). These data also indicate that biological metrics are more strongly associated with episodic memory, executive function, and processing speed than chronological age in older adults with MCI.
Discrepancies exist in reports of social cognition deficits in individuals with premanifest Huntington’s disease (HD); however, the reason for this variability has not been investigated. The aims of this study were to (1) evaluate group- and individual-level social cognitive performance and (2) examine intra-individual variability (dispersion) across social cognitive domains in individuals with premanifest HD.
Method:
Theory of mind (ToM), social perception, empathy, and social connectedness were evaluated in 35 individuals with premanifest HD and 29 healthy controls. Cut-off values beneath the median and 1.5 × the interquartile range below the 25th percentile (P25 – 1.5 × IQR) of healthy controls for each variable were established for a profiling method. Dispersion between social cognitive domains was also calculated.
Results:
Compared to healthy controls, individuals with premanifest HD performed worse on all social cognitive domains except empathy. Application of the profiling method revealed a large proportion of people with premanifest HD fell below healthy control median values across ToM (>80%), social perception (>57%), empathy (>54%), and social behaviour (>40%), with a percentage of these individuals displaying more pronounced impairments in empathy (20%) and ToM (22%). Social cognition dispersion did not differ between groups. No significant correlations were found between social cognitive domains and mood, sleep, and neurocognitive outcomes.
Conclusions:
Significant group-level social cognition deficits were observed in the premanifest HD cohort. However, our profiling method showed that only a small percentage of these individuals experienced marked difficulties in social cognition, indicating the importance of individual-level assessments, particularly regarding future personalised treatments.
The National Neuropsychology Network (NNN) is a multicenter clinical research initiative funded by the National Institute of Mental Health (NIMH; R01 MH118514) to facilitate neuropsychology’s transition to contemporary psychometric assessment methods with resultant improvement in test validation and assessment efficiency.
Method:
The NNN includes four clinical research sites (Emory University; Medical College of Wisconsin; University of California, Los Angeles (UCLA); University of Florida) and Pearson Clinical Assessment. Pearson Q-interactive (Q-i) is used for data capture for Pearson published tests; web-based data capture tools programmed by UCLA, which serves as the Coordinating Center, are employed for remaining measures.
Results:
NNN is acquiring item-level data from 500–10,000 patients across 47 widely used Neuropsychology (NP) tests and sharing these data via the NIMH Data Archive. Modern psychometric methods (e.g., item response theory) will specify the constructs measured by different tests and determine their positive/negative predictive power regarding diagnostic outcomes and relationships to other clinical, historical, and demographic factors. The Structured History Protocol for NP (SHiP-NP) helps standardize acquisition of relevant history and self-report data.
Conclusions:
NNN is a proof-of-principle collaboration: by addressing logistical challenges, NNN aims to engage other clinics to create a national and ultimately an international network. The mature NNN will provide mechanisms for data aggregation enabling shared analysis and collaborative research. NNN promises ultimately to enable robust diagnostic inferences about neuropsychological test patterns and to promote the validation of novel adaptive assessment strategies that will be more efficient, more precise, and more sensitive to clinical contexts and individual/cultural differences.
To characterize and compare the neuropsychological profiles of patients with primary progressive apraxia of speech (PPAOS) and apraxia of speech with progressive agrammatic aphasia (AOS-PAA).
Method:
Thirty-nine patients with PPAOS and 49 patients with AOS-PAA underwent formal neurological, speech, language, and neuropsychological evaluations. Cognitive domains assessed included immediate and delayed episodic memory (Wechsler Memory Scale-Third edition; Logical Memory; Visual Reproduction; Rey Auditory Verbal Learning Test), processing speed (Trail Making Test A), executive functioning (Trail Making Test B; Delis-Kaplan Executive Functioning Scale – Sorting), and visuospatial ability (Rey-Osterrieth Complex Figure copy).
Results:
The PPAOS patients were cognitively average or higher in the domains of immediate and delayed episodic memory, processing speed, executive functioning, and visuospatial ability. Patients with AOS-PAA performed more poorly on tests of immediate and delayed episodic memory and executive functioning compared to those with PPAOS. For every 1 unit increase in aphasia severity (e.g. mild to moderate), performance declined by 1/3 to 1/2 a standard deviation depending on cognitive domain. The degree of decline was stronger within the more verbally mediated domains, but was also notable in less verbally mediated domains.
Conclusion:
The study provides neuropsychological evidence further supporting the distinction of PPAOS from primary progressive aphasia and should be used to inform future diagnostic criteria. More immediately, it informs prognostication and treatment planning.
Severe acute respiratory syndrome (SARS) is a highly contagious viral respiratory illness associated with hypoxia and dyspnea. Many of those who contracted and recovered from SARS during the 2002–2003 outbreak reported persistent physical, psychological, and cognitive difficulties. Here, we investigated the residual influences of SARS on cognition for a subset of healthcare professionals who recovered and were referred for neuropsychological evaluation through their workplace insurance.
Method:
Twenty-eight healthcare professionals were evaluated on neuropsychological and mood functioning approximately 1.5 years post-recovery from a severe respiratory illness. Test scores were compared with age-matched normative data, and correlations were examined between mood, self-report memory scales, subjective complaints (e.g., poor concentration, pain, fatigue), illness severity (i.e., length of hospitalization, oxygen use during hospital stay), and cognitive performance.
Results:
Participants performed within age expectations on the majority of cognitive measures including overall memory ability. Although processing speed was generally within normal limits, 43% showed significant speed–accuracy trade-offs favoring accuracy over maintaining speed. Deficits were observed on measures of complex attention, such as working memory and the ability to sustain attention under conditions of distraction. Participants endorsed poorer memory ability than same-age peers on a meta-memory measure and mild to moderate depression and anxiety symptoms. Objective test performance was largely uncorrelated with self-reports, mood, or illness severity, except for moderate correlations between complex attention and participants’ subjective ratings of Everyday Task-Oriented Memory.
Conclusions:
These findings demonstrate specific long-term cognitive deficits associated with SARS and provide further evidence of the cognitive effects of hypoxic illnesses.
Deficits in episodic memory are frequently reported after ischemic stroke. In standard clinical care, episodic memory is assessed after a 20–30 min delay, with abnormal memory decay over this period being characterized as rapid forgetting (RF). Previous studies have shown abnormal forgetting over a prolonged interval (days to weeks) despite normal acquisition, referred to as accelerated long-term forgetting (ALF).
Method:
We examined whether ALF is present in stroke patients (N = 91) using immediate testing (T1), testing after a short delay (20–30 min, T2), and testing after a prolonged delay (one week, T3). Based on performance compared to matched controls (N = 85), patients were divided into (1) patients without forgetting, (2) patients with RF between T1 and T2, and (3) patients with ALF at T3. Furthermore, confidence ratings were assessed.
Results:
ALF was present in a moderate amount of stroke patients (17%), but ALF was even more prevalent in our stroke sample than RF after a 20–30 min delay (which was found in only 13% of our patients). Patients reported a lower confidence for their responses, independent of their actual performance.
Conclusions:
Adding a one-week delayed measurement may potentially assist in identifying patients with memory decrements that may otherwise go undetected.
Examine pre-existing learning disorders (LD) and attention deficit/hyperactivity disorders (ADHD) as risk factors for prolonged recovery and increased symptomology following pediatric mild traumatic brain injury (mTBI).
Methods:
We conducted a retrospective cohort study of children/adolescents (5-17 years) with mTBI who presented to a Children’s Minnesota Concussion Clinic between April 2018 and March 2019. Differences across strata of pre-existing conditions (present vs. absent) in time to recovery measures were estimated via Kaplan–Meier and Cox proportional hazards analyses and differences in symptom trajectories were examined via linear mixed-effects regression models. Regression models were adjusted for age, sex and other confounders.
Results:
In our cohort of 680 mTBI patients, those with LD (n = 70) or ADHD (n = 107) experienced significantly longer median durations of symptoms (58 and 68 days, respectively) than those without (43 days). Accordingly, LD was significantly associated with delayed symptom recovery (adjusted hazard ratio (aHR) = 1.63, 95% CI: 1.16–2.29), return to school (1.47, 1.08–2.00), and return to physical activity (1.50, 1.10–2.04). Likewise, ADHD was associated with delayed recovery (1.69, 1.28–2.23), return to school (1.52, 1.17–1.97) and physical activity (1.55, 1.19–2.01). Further, patients with LD or ADHD reported, on average, significantly more concussion symptoms and higher vision symptom scores throughout recovery versus those without. There was no evidence that concussion or vision symptom recovery trajectories varied over time between those with/without LD or ADHD (joint P-interactions > 0.05).
Conclusion:
Pre-existing LD and ADHD are risk factors for prolonged and more symptomatic mTBI recovery in youth. These results can inform clinical concussion management and recovery expectations.
To test the hypothesis that higher level of purpose in life is associated with lower likelihood of dementia and mild cognitive impairment (MCI) in older Brazilians.
Methods:
As part of the Pathology, Alzheimer’s and Related Dementias Study (PARDoS), informants of 1,514 older deceased Brazilians underwent a uniform structured interview. The informant interview included demographic data, the Clinical Dementia Rating scale to diagnose dementia and MCI, the National Institute of Mental Health Diagnostic Interview Schedule for depression, and a 6-item measure of purpose in life, a component of well-being.
Results:
Purpose scores ranged from 1.5 to 5.0 with higher values indicating higher levels of purpose. On the Clinical Dementia Rating Scale, 940 persons (62.1%) had no cognitive impairment, 121 (8.0%) had MCI, and 453 (29.9%) had dementia. In logistic regression models adjusted for age at death, sex, education, and race, higher purpose was associated with lower likelihood of MCI (odds ratio = .58; 95% confidence interval [CI]: .43, .79) and dementia (odds ratio = .49, 95% CI: .41, .59). Results were comparable after adjusting for depression (identified in 161 [10.6%]). Neither race nor education modified the association of purpose with cognitive diagnoses.
Conclusions:
Higher purpose in life is associated with lower likelihood of MCI and dementia in older black and white Brazilians.
In the neuroHIV literature, cognitive reserve has most often been operationalized using education, occupation, and IQ. The effects of other cognitively stimulating activities that might be more amenable to interventions have been little studied. The purpose of this study was to develop an index of cognitive reserve in people with HIV, combining multiple indicators of cognitively stimulating lifetime experiences into a single value.
Methods:
The data set was obtained from a Canadian longitudinal study (N = 856). Potential indicators of cognitive reserve captured at the study entry included education, occupation, engagement in six cognitively stimulating activities, number of languages spoken, and social resources. Cognitive performance was measured using a computerized test battery. A cognitive reserve index was formulated using logistic regression weights. For the evidence on concurrent and predictive validity of the index, the measures of cognition and self-reported everyday functioning were each regressed on the index scores at study entry and at the last follow-up [mean duration: 25.9 months (SD 7.2)], respectively. Corresponding regression coefficients and 95% confidence intervals (CIs) were computed.
Results:
Professional sports [odds ratio (OR): 2.9; 95% CI 0.59–14.7], visual and performance arts (any level of engagement), professional/amateur music, complex video gaming and competitive games, and travel outside North America were associated with higher cognitive functioning. The effects of cognitive reserve on the outcomes at the last follow-up visit were closely similar to those at study entry.
Conclusion:
This work contributes evidence toward the relative benefit of engaging in specific cognitively stimulating life experiences in HIV.
To evaluate the properties of the cognitive battery used in the MIND Diet Intervention to Prevent Alzheimer’s Disease. The MIND Diet Intervention is a randomized control trial to determine the relative effectiveness of the MIND diet in slowing cognitive decline and reducing brain atrophy in older adults at risk for Alzheimer’s dementia.
Methods:
The MIND cognitive function battery was administered at baseline to 604 participants of an average age of 70 years, who agreed to participate in the diet intervention study, and was designed to measure change over time. The battery included 12 cognitive tests, measuring the 4 cognitive domains of executive function, perceptual speed, episodic memory, and semantic memory. We conducted a principal component analysis to examine the consistency between our theoretical domains and the statistical performance of participants in each domain. To further establish the validity of each domain, we regressed the domain scores against a late-life cognitive activity score, controlling for age, race, sex, and years of education.
Results:
Four factors emerged in the principal component analyses that were similar to the theoretical domains. In regression equations, we found the expected associations with age, education, and late-life cognitive activity with each of the four cognitive domains.
Conclusions:
These results indicate that the MIND cognitive battery is a comprehensive and valid battery of four separate domains of cognitive function that can be used in diet intervention trials for older adults.
Executive functions (EF) and focal attention have been identified as a weakness in the profile of 22q11.2 deletion syndrome (22q11DS). However, due to a high variety of tasks used across previous studies, it remains unclear whether impairments may be more pronounced for specific subdomains of EF and focal attention. Furthermore, age-related changes have only been examined in a few studies, so far only yielding a partial view of the overall developmental profile.
Method:
In a broad age range (8–35 years) composed of longitudinal data, 183 participants (103 diagnosed with 22q11DS) completed an extensive assessment of EF and attention. To get a more comprehensive overview of specific versus global impairments, several tasks were assessed within multiple domains.
Results:
Results suggest differential impairments and trajectories in specific EF subdomains. Specifically, our findings suggest that individuals with 22q11DS not only showed lower overall inhibition skills, but also that initiation skills developed at a slower pace compared to healthy controls. Results are less clear regarding cognitive flexibility, updating and focal attention, for which performance strongly depended on the tasks that was selected to assess the domain.
Conclusions:
Findings confirm and extend knowledge on differential developmental patterns of EF and attention domains in 22q11DS. They further stress the necessity to administer extensive, multifaceted evaluations to gain a more reliable overview of patients’ cognitive profile.
Patients with Neurofibromatosis Type 1 (NF1) frequently display symptoms resembling those of Attention Deficit/Hyperactivity Disorder (ADHD). Importantly, these disorders are characterised by distinct changes in the dopaminergic system, which plays an important role in timing performance and feedback-based adjustments in timing performance. In a transdiagnostic approach, we examine how far NF1 and ADHD show distinct or comparable profiles of timing performance and feedback-based adjustments in timing.
Method:
We examined time estimation and learning processes in healthy control children (HC), children with ADHD with predominantly inattentive symptoms and those with NF1 using a feedback-based time estimation paradigm.
Results:
Healthy controls consistently responded closer to the correct time window than both patient groups, were less variable in their reaction times and displayed intact learning-based adjustments across time. The patient groups did not differ from each other regarding the number of in-time responses. In ADHD patients, the performance was rather unstable across time. No performance changes could be observed in patients with NF1 across the entire task.
Conclusions:
Children with ADHD and NF1 differ in feedback learning-based adjustments of time estimation processes. ADHD is characterised by behavioural fluctuations during the learning process. These are likely to be associated with inefficiencies in the dopaminergic system. NF1 is characterised by impairments of feedback learning which could be due to various neurotransmitter alterations occurring in addition to deficits in dopamine synthesis. Results show that despite the strong overlap in clinical phenotype and neuropsychological deficits between NF1 and ADHD, the underlying cognitive mechanisms are different.
This study is based on long-term follow-up of participants in a randomized double-blind sham surgery-controlled trial (1995–1999) designed to determine the effectiveness of implantation of human embryonic mesencephalic tissue containing dopamine neuron precursors into the brains of patients with advanced Parkinson’s disease (PD). We investigated differences between long-term survivors and nonsurvivors at baseline in order to contribute to information regarding optimal patient selection for upcoming stem cell trials.
Method:
Forty participants were randomly assigned to receive either neural implantation or sham surgery. Thirty-four patients who ultimately received the implant were followed periodically with the most recent assessment occurring in 2015–2016. Demographic information, neurological measures, positron emission tomography (PET) imaging, neuropsychological assessments, and a personality assessment were included in the current analyses. T-tests were used to compare survivors and nonsurvivors. Logistic regression analyses examined predictors of survivorship.
Results:
Five of six survivors were female. They were younger than nonsurvivors (p = .03) and more neuropsychologically “intact” across a broad range of cognitive areas (significance levels ranged from <.001 to .045). There were no differences between survivors and nonsurvivors off medications at baseline on neurological or PET assessments. Survivors reported more “Openness to Experience” (p = .004) than nonsurvivors. Using empirically derived predictor variables, results of logistic regression analyses indicated that Animal Naming (cognitive task) and Openness to Experience (personality variable) were the strongest predictors of survivorship.
Conclusions:
Variables to consider when selecting participants for future cell-based therapies include being “intact” neuropsychologically, level of Openness to Experience, younger age, and inclusion of women.
Exercise has been found to be important in maintaining neurocognitive health. However, the effect of exercise intensity level remains relatively underexplored. Thus, to test the hypothesis that self-paced high-intensity exercise and cardiorespiratory fitness (peak aerobic capacity; VO2peak) increase grey matter (GM) volume, we examined the effect of a 6-month exercise intervention on frontal lobe GM regions that support the executive functions in older adults.
Methods:
Ninety-eight cognitively normal participants (age = 69.06 ± 5.2 years; n = 54 female) were randomised into either a self-paced high- or moderate-intensity cycle-based exercise intervention group, or a no-intervention control group. Participants underwent magnetic resonance imaging and fitness assessment pre-intervention, immediately post-intervention, and 12-months post-intervention.
Results:
The intervention was found to increase fitness in the exercise groups, as compared with the control group (F = 9.88, p = <0.001). Changes in pre-to-post-intervention fitness were associated with increased volume in the right frontal lobe (β = 0.29, p = 0.036, r = 0.27), right supplementary motor area (β = 0.30, p = 0.031, r = 0.29), and both right (β = 0.32, p = 0.034, r = 0.30) and left gyrus rectus (β = 0.30, p = 0.037, r = 0.29) for intervention, but not control participants. No differences in volume were observed across groups.
Conclusions:
At an aggregate level, six months of self-paced high- or moderate-intensity exercise did not increase frontal GM volume. However, experimentally-induced changes in individual cardiorespiratory fitness was positively associated with frontal GM volume in our sample of older adults. These results provide evidence of individual variability in exercise-induced fitness on brain structure.
We examined parent- and adolescent-reported executive functioning (EF) behaviors following pediatric traumatic brain injury (TBI) in the context of Online Family Problem-Solving Therapy (OFPST) and moderators of change in EF behaviors.
Method:
In total, 274 families were randomized to OFPST or an internet resource comparison group. Parents and adolescents completed the Behavior Rating Inventory of Executive Function at four time points. Mixed models were used to examine EF behaviors, assessing the effects of visit, treatment group, rater, TBI severity, age, socioeconomic status, and family functioning.
Results:
Parents rated their adolescents’ EF as poorer (F(3,1156) = 220.15, p < .001; M = 58.11, SE = 0.73) than adolescents rated themselves (M = 51.81, SE = 0.73). Across raters, EF behaviors were poorer for adolescents whose parents had less education (F(3,1156) = 8.60, p = .003; M = 56.76, SE = 0.98) than for those with more education (M = 53.16, SE = 0.88). Age at baseline interacted with visit (F(3,1156) = 5.05, p = .002), such that families of older adolescents reported improvement in EF behaviors over time. Family functioning also interacted with visit (F(3, 1156) = 2.61, p = .049), indicating more improvement in EF behaviors over time in higher functioning families. There were no effects of treatment or TBI severity.
Conclusion:
We identified a discrepancy between parent- and adolescent-reported EF, suggesting reduced awareness of deficits in adolescents with TBI. We also found that poorer family functioning and younger age were associated with poorer recovery after TBI, whereas adolescents of parents with less education were reported as having greater EF deficits across time points.