Long-term Memory Testing in Children With Typical Development and Neurodevelopmental Disorders: Remote Web-based Image Task Feasibility Study.

BACKGROUND: Neurodevelopmental disorders (NDD) cause individuals to have difficulty in learning facts, procedures, or social skills. NDD has been linked to several genes, and several animal models have been used to identify potential therapeutic candidates based on specific learning paradigms for long-term and associative memory. In individuals with NDD, however, such testing has not been used so far, resulting in a gap in translating preclinical results to clinical practice. OBJECTIVE: We aim to assess if individuals with NDD could be tested for paired association learning and long-term memory deficit, as shown in previous animal models. METHODS: We developed an image-based paired association task, which can be performed at different time points using remote web-based testing, and evaluated its feasibility in children with typical development (TD), as well as NDD. We included 2 tasks: object recognition as a simpler task and paired association. Learning was tested immediately after training and also the next day for long-term memory. RESULTS: We found that children aged 5-14 years with TD (n=128) and with NDD of different types (n=57) could complete testing using the Memory Game. Children with NDD showed deficits in both recognition and paired association tasks on the first day of learning, in both 5-9-year old (P<.001 and P=.01, respectively) and 10-14-year old groups (P=.001 and P<.001, respectively). The reaction times to stimuli showed no significant difference between individuals with TD or NDD. Children with NDD exhibited a faster 24-hour memory decay for the recognition task than those with TD in the 5-9-year old group. This trend is reversed for the paired association task. Interestingly, we found that children with NDD had their retention for recognition improved and matched with typically developing individuals by 10-14 years of age. The NDD group also showed improved retention deficits in the paired association task at 10-14 years of age compared to the TD group. CONCLUSIONS: We showed that web-based learning testing using simple picture association is feasible for children with TD, as well as with NDD. We showed how web-based testing allows us to train children to learn the association between pictures, as shown in immediate test results and those completed 1 day after. This is important as many models for learning deficits in NDD target both short- and long-term memory for therapeutic intervention. We also demonstrated that despite potential confounding factors, such as self-reported diagnosis bias, technical issues, and varied participation, the Memory Game shows significant differences between typically developing children and those with NDD. Future experiments will leverage this potential of web-based testing for larger cohorts and cross-validation with other clinical or preclinical cognitive tasks.

Patterns of preschool children's screen time, parent-child interactions, and cognitive development in early childhood: a pilot study.

BACKGROUND: The primary objective of this study was to explore the feasibility of a virtual study protocol for a future longitudinal study, including recruitment, study measures, and procedures. The secondary objective was to examine preliminary hypotheses of associations, including 1) the correlations between total duration and patterns of screen time and cognitive development, and 2) the differences in quality of parent-child interactions for two screen-based tasks and a storybook reading task. METHODS: Participants included 44 children aged 3 years and their parents from Edmonton, Alberta and surrounding areas. Children's screen time patterns (i.e., type, device, content, context) were parental-reported using a 2-week online daily diary design. Children's cognitive development (i.e., working memory, inhibitory control, self-control, and language) was measured virtually through a recorded Zoom session. Parent-child interactions during three separate tasks (i.e., video, electronic game, and storybook reading) were also measured virtually through a separate recorded Zoom session (n = 42). The quality of the interactions was determined by the Parent-Child Interaction System (PARCHISY). Descriptive statistics, Intra-class correlations (ICC), Spearman's Rho correlations, and a one-way repeated measures ANOVA with a post-hoc Bonferroni test were conducted. RESULTS: All virtual protocol procedures ran smoothly. Most (70%) participants were recruited from four 1-week directly targeted Facebook ads. High completion rates and high inter-rater reliability in a random sample (Diary: 95% for 13/14 days; Cognitive development: 98% 3/4 tests, ICC > 0.93; Parent-child interactions: 100% for 3 tasks, Weighted Kappa ≥ 0.84) were observed for measures. Across cognitive development outcomes, medium effect sizes were observed for five correlations, with positive correlations observed with certain content (i.e., educational screen time) and negative associations observed for total screen time and certain types (show/movie/video viewing) and contexts (i.e., co-use). Medium and large effect sizes were observed for the differences in parent-child interaction quality between the three tasks. CONCLUSIONS: The virtual study protocol appeared feasible. Preliminary findings suggest it may be important to go beyond total duration and consider type, content, and context when examining the association between screen time and cognitive development. A future longitudinal study using this virtual protocol will be conducted with a larger and more generalizable sample.

Exploring the interplay of dopaminergic genotype and parental behavior in relation to executive function in early childhood.

Child genotype is an important biologically based individual difference conferring differential sensitivity to the effect of parental behavior. This study explored dopaminergic polygenic composite × parental behavior interactions in relation to young children's executive function. Participants were 135 36-month-old children and their mothers drawn from a prospective cohort followed longitudinally from pregnancy. A polygenic composite was created based on the number of COMT, DAT1, DRD2, and DRD4 alleles associated with increased reward sensitivity children carried. Maternal negative reactivity and responsiveness were coded during a series of structured mother-child interactions. Executive function was operationalized as self-control and working memory/inhibitory control. Path analysis supported a polygenic composite by negative reactivity interaction for self-control. The nature of the interaction was one of diathesis-stress, such that higher negative reactivity was associated with poorer self-control for children with higher polygenic composite scores. This result suggests that children with a higher number of alleles may be more vulnerable to the negative effect of negative reactivity. Negative reactivity may increase the risk for developing behavior problems in this population via an association with poorer self-control. Due to the small sample size, these initial findings should be treated with caution until they are replicated in a larger independent sample.

Differential Relations of Parental Behavior to Children's Early Executive Function as a Function of Child Genotype: A Systematic Review.

Child genotype is an important biologically based indicator of sensitivity to the effects of parental behavior on children's executive function (EF) in early childhood, birth to age 5. While evidence for gene × parental behavior interactions on children's early EF is growing, researchers have called the quality of evidence provided by gene × environment interaction studies into question. For this reason, this review comprehensively examined the literature and evaluated the evidence for gene × parental behavior interactions on children's early EF abilities. Psychology and psychiatry databases were searched for published peer-reviewed studies. A total of 18 studies met inclusion criteria. Twenty-nine of 89 (33%) examined interactions were significant. However, a p-curve analysis did not find the significant interactions to be of evidential value. A high rate of false positives, due to the continued use of candidate gene and haplotype measures of child genotype and small sample sizes, likely contributed to the high rate of significant interactions and low evidential value. The use of contemporary molecular genetic measures and larger sample sizes are necessary to advance our understanding of child genotype as a moderator of parental effects on children's EF during early childhood and the biopsychosocial mechanisms underlying children's EF development during this critical period. Without these changes, future research is likely to be stymied by the same limitations as current research.

Differential associations of maternal behavior to preschool boys' and girls' executive function.

Boys are more sensitive to environmental factors like parental behavior, an important predictor of executive function. This study examined whether the interaction between child sex and maternal behavior was associated with children's executive function in a manner consistent with the vulnerability or differential susceptibility model. Participants were 146 36-month-old children and their mothers. Maternal responsiveness and negative reactivity were coded during structured mother-child interactions. Executive function was operationalized as latent self-control and working memory/inhibitory control (WMIC). Structural equation modelling supported a sex by responsiveness interaction for self-control but not WMIC. Consistent with a vulnerability model, less responsiveness was associated with poorer self-control for boys relative to girls. Boys' self-control may be more vulnerable to the negative effect of unresponsive maternal behavior helping explain boys increased risk for externalizing behavior problems.

Using a robotic teleoperation system for haptic exploration.

INTRODUCTION: When children with physical impairments cannot perform hand movements for haptic exploration, they miss opportunities to learn about object properties. Robotics systems with haptic feedback may better enable object exploration. METHODS: Twenty-four adults and ten children without physical impairments, and one adult with physical impairments, explored tools to mix substances or transport different sized objects. All participants completed the tasks with both a robotic system and manual exploration. Exploratory procedures used to determine object properties were also observed. RESULTS: Adults and children accurately identified appropriate tools for each task using manual exploration, but they were less accurate using the robotic system. The adult with physical impairment identified appropriate tools for transport in both conditions, however had difficulty identifying tools used for mixing substances. A new exploratory procedure was observed, Tapping, when using the robotic system. CONCLUSIONS: Adults and children could make judgements on tool utility for tasks using both manual exploration and the robotic system, however they experienced limitations in the robotics system that require more study. The adult with disabilities required less assistance to explore tools when using the robotic system. The robotic system may be a feasible way for individuals with physical disabilities to perform haptic exploration.

Integrating Three Characteristics of Executive Function in Non-Demented Aging: Trajectories, Classification, and Biomarker Predictors.

OBJECTIVE: With longitudinal executive function (EF) data from the Victoria Longitudinal Study, we investigated three research goals pertaining to key characteristics of EF in non-demented aging: (a) examining variability in EF longitudinal trajectories, (b) establishing trajectory classes, and (c) identifying biomarker predictors discriminating these classes. METHOD: We used a trajectory analyses sample (n = 781; M age = 71.42) for the first and second goals and a prediction analyses sample (n = 570; M age = 70.10) for the third goal. Eight neuropsychological EF measures were used as indicators of three EF dimensions: inhibition, updating, and shifting. Data-driven classification analyses were applied to the full trajectory distribution. Machine learning prediction analyses tested 15 predictors from genetic, functional, lifestyle, mobility, and demographic risk domains. RESULTS: First, we observed: (a) significant variability in EF trajectories over a 40-year band of aging and (b) significantly variable patterns of EF decline. Second, a four-class EF trajectory model was observed, characterized with classes differentiated by an algorithm of level and slope information. Third, the highest group class was discriminated from lowest by several prediction factors: more education, more novel cognitive activity, lower pulse pressure, younger age, faster gait, lower body mass index, and better balance. CONCLUSION: First, with longitudinal variability in EF aging, the data-driven approach showed that long-term trajectories can be differentiated into separable classes. Second, prediction analyses discriminated class membership by a combination of multiple biomarkers from demographic, lifestyle, functional, and mobility domains of risk for brain and cognitive aging decline.

Effect of feedback and target size on eye gaze accuracy in an off-screen task.

PURPOSE: Eye gaze interfaces have been used by people with severe physical impairment to interact with various assistive technologies. If used to control robots, it would be beneficial if individuals could gaze directly at targets in the physical environment rather than have to switch their gaze between a screen with representations of robot commands and the physical environment to see the response of their selection. By using a homogeneous transformation technique, eye gaze coordinates can be mapped between the reference coordinate frame of eye tracker and the coordinate frame of objects in the physical environment. Feedback about where the eye tracker has determined the eye gaze is fixated is needed so users can select targets more accurately. Screen-based assistive technologies can use visual feedback, but in a physical environment, other forms of feedback need to be examined. MATERIALS AND METHODS: In this study, an eye gaze system with different feedback conditions (i.e., visual, auditory, vibrotactile, and no-feedback) was tested when participants received visual feedback on a display (on-screen) and when looking directly at the physical environment (off-screen). Target selection tasks in both screen conditions were performed by ten non-disabled adults, three non-disabled children, and two adults and one child with cerebral palsy. RESULTS: Tasks performed with gaze fixation feedback modalities were accomplished faster and with higher success than tasks performed without feedback, and similar results were observed in both screen conditions. No significant difference was observed in performance across the feedback modalities, but participants had personal preferences. CONCLUSION: The homogeneous transformation technique enabled the use of a stationary eye tracker to select target objects in the physical environment, and auditory and vibrotactile feedback enabled participants to be more accurate selecting targets than without it.Implications for RehabilitationBeing able to select target objects in the physical environment by eye gaze could make it easier for children with disabilities to control assistive robots, because in this way they do not have to change their focus between a computer screen with commands and the robot.Providing auditory or vibrotactile feedback when using an eye gaze system made it faster and easier to know if a target was being gazed upon.Being able to select targets in the environment using eye gaze could be beneficial for other assistive technology, too, such as destination selection for power wheelchairs.

Body mass index predicts cognitive aging trajectories selectively for females: Evidence from the Victoria Longitudinal Study.

OBJECTIVE: Elevated body weight in midlife is an established risk factor for accelerated cognitive decline, impairment, and dementia. Research examining the impact of later-life body mass index (BMI) on normal cognitive aging has produced mixed results. There is a need for longitudinal designs, replication across multiple cognitive domains, and consideration of BMI effects in the context of important moderators. The present research examined (a) BMI prediction of neuropsychological performance and decline in executive function (EF), neurocognitive speed, and memory and (b) sex stratification of BMI effects. METHOD: Participants (n = 869; 573 females; M age = 71.75, range = 53-85 years) were older adults from the Victoria Longitudinal Study. Latent growth modeling was used to examine BMI as a predictor of level and change in three latent variables of cognition. The data were then stratified by sex to test whether BMI effects differed for females and males. We adjusted for selected medical, psychosocial, and demographic characteristics. RESULTS: Higher BMI predicted less decline in EF, neurocognitive speed, and memory. Interestingly, when the data were stratified by sex, higher BMI predicted less neuropsychological decline across domains for females only. BMI was unrelated to cognitive aging trajectories for males. CONCLUSIONS: We found that elevated BMI was a risk-reducing factor for cognitive decline only for females. Results may be used to enhance the precision with which intervention protocols may target specific subgroups of older adults. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Testing of an assistive robot system for haptic exploration of objects.

INTRODUCTION: When children with physical impairments cannot perform hand movements for haptic exploration, they may miss opportunities to learn the properties of objects. Assistive robots may enable them to make manipulation actions. OBJECTIVE: To examine the differences between using a robotic teleoperation system with haptic feedback and manual exploration when making perceptual comparisons about object properties. Accuracy and exploratory procedures (EP) using the system were compared to those in manual exploration. METHOD: Twenty adults without physical disabilities and ten typically developing children manipulated four pairs of objects and chose one based on size, roughness, hardness and shape. All participants completed the task with the robotic system (Tech) and manual exploration (No Tech), with the order counterbalanced. RESULTS AND CONCLUSION: Participants performed a previously unidentified EP, "tapping", in the Tech condition. Enclosure was not possible with the robot end effector, but tapping afforded the required perceptual information. Adults' perceptual comparisons were always accurate and they predominantly performed the optimum EP in both conditions. Even when children performed the optimum EP with the system, their answers were less accurate than with manual exploration. Most gave the correct answer, except for hardness, which was likely due to mechanical flexibility in the robotic system.

Socioeconomic status and executive function in early childhood: Exploring proximal mechanisms.

Although there is substantial evidence that socioeconomic status (SES) predicts children's executive function (EF), the mechanisms underlying this association are poorly understood. This study tested the utility of two theories proposed to link SES to children's EF: the family stress model and the family investment model. Data came from the Midwestern Infant Development Study (N = 151). To measure SES, parental education and income were assessed during pregnancy, and income was also assessed when children were 6 and 36 months old. Children's EF, operationalized as working memory/inhibitory control (WMIC) and self-control, was assessed at 36 months of age, along with potential mediators including maternal psychological distress, harsh parenting, and cognitive stimulation. Using structural equation modeling, we tested simultaneous pathways from SES to EF: (a) via maternal psychological distress to harsh parenting (family stress model) and (b) via cognitive stimulation (family investment model). Of the SES measures, lower education predicted poorer WMIC directly and indirectly via greater maternal psychological distress. Lower education also predicted poorer self-control via greater maternal psychological distress. This effect was partially suppressed by an indirect path from lower education to better self-control via greater psychological distress and increased harsh parenting. Cognitive stimulation did not act as a mediator. Income was not directly or indirectly associated with EF. These findings provide partial support for the family stress model and suggest that family functioning is an important proximal mechanism for children's EF development. This study also highlights the importance of considering SES as a multidimensional construct.

Does early maternal responsiveness buffer prenatal tobacco exposure effects on young children's behavioral disinhibition?

Children with prenatal tobacco exposure (PTE) exhibit early self-regulatory impairments, reflecting a life-course persistent propensity toward behavioral disinhibition. Previously, we demonstrated the protective role of parental responsiveness for reducing the risk of exposure-related disruptive behavior in adolescence. Here, we expanded this line of inquiry, examining whether responsiveness moderates the relation of PTE to a broader set of behavioral disinhibition features in early childhood and testing alternative diathesis-stress versus differential susceptibility explanatory models. PTE was assessed prospectively using interviews and bioassays in the Midwestern Infant Development Study (MIDS). Mother-child dyads (N = 276) were re-assessed at approximately 5 years of age in a preschool follow-up. We quantified maternal responsiveness and child behavioral disinhibition using a combination of directly observed activities in the lab and developmentally sensitive questionnaires. Results supported a diathesis-stress pattern. Children with PTE and less responsive mothers showed increased disruptive behavior and lower effortful control compared with children without PTE. In contrast, exposed children with more responsive mothers had self-regulatory profiles similar to their non-exposed peers. We did not observe sex differences. Findings provide greater specification of the protective role of maternal responsiveness for self-regulation in children with PTE and help clarify mechanisms that may underscore trajectories of exposure-related behavioral disinhibition.

Valence matters: An electrophysiological study on how emotions influence cognitive performance in children.

Emotional stimuli have been found to influence cognitive performance in children, but it is not clear whether this effect varies with the cognitive demands of the task. In this study, we examined how emotional expressions influenced cognitive performance and event-related potentials (ERPs) in early and middle childhood under varying cognitive control demands. Two groups of children (4.5-6.0 and 7.0-8.5 years) completed a modified flanker task where the stimuli were faces displaying task-irrelevant emotional expressions. Emotional influence varied depending on emotional valence: Accuracy was greater for happy targets, while response time and N2 latency were longer for angry targets. In younger children only, angry targets elicited a larger late frontal negativity. Cognitive control demands did not modulate the effect of emotions on behavioral performance or ERPs, contrasting with findings in adults. Findings are discussed in relation to the dual competition model and previous work demonstrating a positivity bias in children.

Language Dominance and Cognitive Flexibility in French-English Bilingual Children.

Some studies have reported a cognitive advantage for bilingual children over monolinguals and other studies have not. One possible reason for these conflicting results is that the degree of cognitive flexibility is related to individual differences in language dominance and use. More balanced bilinguals who separate their languages by context might have to learn to reduce inter-language interference and therefore show greater cognitive flexibility. The goal of the present study was to test if language dominance is related to French-English bilingual children's cognitive flexibility, using three different measures of language dominance: (1) parental reports of dominance, (2) relative scores on vocabulary tests, and (3) knowledge of translation equivalents. We also included two measures of language use: (1) living in a bilingual community (Montreal) or a monolingual community (Edmonton) and (2) language separation. Sixty-two French-English bilingual between 46 and 85 months of age participated. Children's cognitive flexibility was assessed using the Advanced Dimensional Change Card Sort task. Children's language knowledge and use was assessed in both French and English using a battery of tests. The results showed that none of the measures of language dominance or language use predicted cognitive flexibility. These results are inconsistent with the claim that individual differences in language dominance and use predict bilinguals' executive function s.

Neural Correlates of Response Inhibition in Early Childhood: Evidence From a Go/No-Go Task.

We examined the neural correlates underlying response inhibition in early childhood. Five-year-old children completed a Go/No-go task with or without time pressure (Fast vs. Slow condition) while scalp EEG was recorded. On No-go trials where inhibition was required, the left frontal N2 and posterior P3 were enhanced relative to Go trials. Time pressure was detrimental to behavioral performance and modulated the early-occurring P1 component. The topography of ERPs related to response inhibition differed from patterns typically seen in adults, and may indicate a compensatory mechanism to make up for immature inhibition networks in children.

Proactive control in early and middle childhood: An ERP study.

Children experience important cognitive control improvements in the transition to school. This study examined 4-5-year-olds' (n=17) and 7-8-year-olds' (n=22) ability to proactively deploy cognitive control. Children performed a cued task-switching paradigm presenting them with a cue indicating which attribute, color or shape, they should use to sort the upcoming stimulus. Following both cue and stimulus, we analyzed two event-related potentials: the P2 and P3, positive peaks reflecting sensory and attentional components of cognitive control, respectively. Following the cue, we also analyzed a positive slow-wave, indexing working memory engagement. We predicted that on switch trials, which required switching tasks, proactive control would result in larger cue-P3 amplitudes, reflecting recognition of the need to switch, and larger slow-wave amplitudes, reflecting maintenance of the new task-sets over the post-cue delay. This pattern was observed in both age groups. At the stimulus, in switch trials, both age groups had shorter stimulus-P2 latencies, consistent with processing facilitation. These results suggest that both 4-5- and 7-8-year-olds engaged cognitive control proactively. Older children, however, demonstrated better performance and larger cue-P2 amplitudes, suggesting more effective proactive control engagement in middle childhood.

Systematic review of physical activity and cognitive development in early childhood.

OBJECTIVES: To comprehensively review all observational and experimental studies examining the relationship between physical activity and cognitive development during early childhood (birth to 5 years). DESIGN: Systematic review. METHODS: Electronic databases were searched in July, 2014. No study design, date, or language limits were imposed on the search. Included studies had to be published, peer reviewed articles that satisfied the a priori determined population (apparently healthy children aged birth to 5 years), intervention (duration, intensity, frequency, or patterns of physical activity), comparator (various durations, intensity, or patterns of physical activity), and outcome (cognitive development) study criteria. Study quality and risk of bias were assessed in December 2014. RESULTS: A total of seven studies, representing 414 participants from five different countries met the inclusion criteria, including two observational and five experimental studies. Six studies found increased or higher duration/frequency of physical activity had statistically significant (p<0.05) beneficial effects on at least one cognitive development outcome, including 67% of the outcomes assessed in the executive function domain and 60% in the language domain. No study found that increased or higher duration/frequency of physical activity had statistically significant detrimental effects on cognitive development. Six of the seven studies were rated weak quality with a high risk of bias. CONCLUSIONS: This review provides some preliminary evidence that physical activity may have beneficial effects on cognitive development during early childhood. Given the shortage of the information and the weak quality of available evidence, future research is needed to strengthen the evidence base in this area.

Apolipoprotein E and Clusterin can magnify effects of personality vulnerability on declarative memory performance in non-demented older adults.

OBJECTIVES: Recent research has linked psychological (personality) factors and specific genetic risk polymorphisms to performance on neurocognitive phenotypes. We examined whether episodic or semantic memory performance is associated with (a) three personality traits (i.e. neuroticism, extraversion, and openness to experience), (b) two neurodegenerative-related polymorphisms (i.e. Apolipoprotein E (APOE; rs7412; rs429358), Clusterin (CLU; rs11136000)), and (c) cross-domain risk interactions (magnification effects). METHODS: Linear growth models were examined to test independent associations between personality traits and declarative memory performance, and potential interaction effects with APOE and CLU genetic risk. Normal older adults (n = 282) with personality and genetic data from the Victoria Longitudinal Study were included at baseline and for up to 14 years of follow-up. RESULTS: First, we observed that higher openness to experience levels were associated with better episodic and semantic memory. Second, three significant gene × personality interactions were associated with poorer memory performance at baseline. These synergistic effects are: (a) APOE allelic risk (ε4+) carriers with lower openness to experience levels, (b) CLU (no risk: T/T) homozygotes with higher extraversion levels, and (c) CLU (no risk: T/T) homozygotes with lower neuroticism levels. CONCLUSIONS: Specific neurodegenerative-related genetic polymorphisms (i.e. APOE and CLU) moderate and magnify the risk contributed by selected personality trait levels (i.e. openness to experience, extraversion) on declarative memory performance in non-demented aging. Future research could target interactions of other personality traits and genetic polymorphisms in different clinical populations to predict other neurocognitive deficits or transitions to cognitive impairment and dementia.

Genetic factors moderate everyday physical activity effects on executive functions in aging: Evidence from the Victoria Longitudinal Study.

OBJECTIVE: Everyday physical activity (EPA) is an important modifiable contributor to age-related variability in executive functioning (EF). However, its role may be moderated by nonmodifiable genetic factors. We tested independent and interactive effects of brain-derived neurotrophic factor (BDNF rs6265) and insulin degrading enzyme (IDE rs6583817) on EF and EPA-EF relationships. METHOD: The sample consisted of genotyped older adults (N = 577; M age = 70.47 years) over 3 waves (∼9 years) of the Victoria Longitudinal Study. Analyses included (a) confirmatory factor analysis establishing a single latent EF factor from 4 standard EF tasks, (b) latent growth modeling over a 40-year band of aging (ages 53 to 95), and (c) structural regression to investigate the independent and interactive effects of BDNF, IDE, and EPA. RESULTS: First, higher levels of EPA were associated with better EF performance at the centering age (75 years) and less EF decline. Second, IDE G+ (protective) carriers exhibited better EF performance at Age 75 than their G- (nonprotective) peers. Third, within the IDE G+ carrier group, those with higher EPA exhibited better EF performance and slower decline over time than those with lower EPA. Fourth, for the BDNF homozygote Val group, higher EPA was associated with better EF performance and more gradual EF change; however, this beneficial effect was not seen for Met carriers. CONCLUSION: The effect of modifiable physical health factors on EF is moderated by biological mechanisms associated with risk-protection genetic polymorphisms.

Alzheimer's Genetic Risk Intensifies Neurocognitive Slowing Associated with Diabetes in Non-Demented Older Adults.

INTRODUCTION: We examine interactive and intensification effects of type 2 diabetes (T2D) with APOE and an Alzheimer's disease Genetic Risk Score (GRS) on neurocognitive speed performance and change in non-demented older adults. METHODS: In an accelerated longitudinal design, we used latent growth modeling to test moderators of level and change in a neurocognitive speed latent variable for 628 adults (baseline M age=69.0) followed over 9 years. The GRS was compiled using the cumulative risk of APOE, CLU, CR1, and PICALM. RESULTS: First, T2D predicted slower speed performance at centering age (75). Second, no predictive effects were associated with APOE or GRS. Third, a significant interaction showed that high risk from both T2D and GRS was selectively associated with steeper longitudinal slowing than all comparison cross-domain risk groups. DISCUSSION: Higher AD-related genetic risk intensified deleterious effects of diabetes on neurocognitive slowing in non-demented aging beyond the independent influence of APOE.