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Age, genetics, and chromosomal sex have been identified as critical risk factors for late-onset Alzheimer's disease (LOAD). The predominant genetic risk factor for LOAD is the apolipoprotein E ε4allele (APOE4), and the prevalence of LOAD is higher in females. However, the translational validity of APOE4mouse models for AD-related cognitive impairment remains to be fully determined. The present study investigated the role of both sex and genotype on learning and memory in aged, humanized APOEknock-in mice. Aged (23.27 mo ± 1.21 mo; 39 male/37 female) APOE3/3, APOE3/4, and APOE4/4mice performed a novel object recognition (NOR) assay. Task-related metrics were analyzed using two-way sex by genotype ANOVAs. Sex differences were more prominent relative to APOEgenotype. Prior to NOR, female mice exhibited thigmotaxic center zone avoidance during the open field task relative to males, regardless of genotype. Within object familiarization and NOR tasks, females had greater object interaction and locomotion. Interestingly, only APOE4/4females on average recognized the novel object. These results suggest that APOE4, although strongly related to LOAD pathogenesis, does not drive cognitive decline in the absence of other risk factors even in very aged mice. Chromosomal sex is a key driver of behavioral phenotypes and thus is a critical variable for translatability of interventions designed to preserve learning and memory in animal models of LOAD. Last, there was a very high degree of variability in behavioral performance across APOEgenotypes. A cluster analysis of the behavioral data revealed a low-activity and a high-activity cluster. APOE4carriers were overrepresented in the low-activity cluster, while male:female distributions did not differ. Collectively, the behavioral data indicate that chromosomal sex has the greatest impact on behavioral phenotype, and APOE4carrier status may confer greater risk for cognitive decline in some animals.

Mild traumatic brain injury (mTBI) can alter the structure of the brain and result in a range of symptoms, including elevated aggression. Neurological damage associated with mTBI is traditionally viewed as transient, yet a growing number of studies suggest long-lasting psychological and neurological changes following mTBI. However, research examining the neural basis of emotion processing in the chronic stage of mTBI recovery remains sparse. In the current study, we utilized resting state functional MRI to explore the association between default mode network connectivity and aggression in 17 healthy controls and 17 adults at least 6 months post-mTBI. The association between within-network connectivity and aggression was examined using general linear models, controlling for the effects of depression. Increased connectivity between the right hippocampus and midcingulate cortex was associated with elevated aggression in adults with mTBI, but not in healthy controls. The results provide evidence for a link between intrinsic functional network disruptions and the manifestation of postconcussive symptoms within chronic stages of recovery following mTBI. These findings expand upon the current research, providing evidence for the use of resting state functional connectivity as a potential biomarker of postconcussive aggression in chronic mTBI.

Previous work suggests that sleep restriction (SR) reduces cognitive control and may increase negative implicit biases. Here we investigated whether SR might influence decision making on a social-evaluative task where individuals had to make judgments of threat based on facial photographs. Furthermore, we investigated the effect of changes in negative implicit biases as a result of sleep restriction on this decision-making task.

This exploratory study uses multimodal approaches to explore undergraduate student engagement via topic emotions and electrodermal activity (EDA) in different engineering design method activities and with different instructional delivery formats (e.g., lecture vs. active learning). The goal of this research is to improve our understanding of how students respond, via engagement, to their engineering design activities during class. This study hypothesizes that students would experience no self‐reported mean changes in topic emotions from their preassessment scores for each engineering design topic and instructional format nor would electrodermal activities (EDA) associate to these topic emotions throughout the design activities. Eighty‐eight freshmen engineering students completed online pretopic and posttopic emotions surveys for five engineering design activities. A subset of 14–18 participants, the focal point of this study, wore an EDA sensor while completing the surveys and participating in these sessions. Preliminary findings suggest that EDA increased for individual and collaborative active learning activities compared to lectures. No significant changes in EDA were found between individual and collaborative active learning activities. Moderate negative correlations were found between EDA and negative topic emotions in the first engineering design activity but not across the rest. At the end of the semester, active learning activities showed higher effect sizes indicating a re‐enforcement of students' engagement in the engineering design method activities. This study provides initial results showing how multimodal approaches can help researchers understand students' closer‐to‐real‐time engagement in engineering design topics and instructional delivery formats.

A number of subjective and objective studies provide compelling evidence of chronic post-concussion changes in sleep, yet very little is known about the acute effects of concussion on sleep quality and quantity. Therefore, the purpose of this prospective pilot study was to use actigraphy to examine the changes in sleep quality and quantity acutely following concussion at home rather than in a hospital or sleep laboratory.

Context:The long-term effects of concussion on brain function during cognitive tasks are not fully understood and neuroimaging findings are equivocal. Some images show hyperactivation of prefrontal brain regions in previously concussed individuals relative to controls, suggesting increased cognitive resource allocation. Others show prefrontal hypoactivation and hyperactivation in other regions as a presumed compensatory mechanism. Given the relationship between sympathetic arousal and neural activation, physiologic measures of arousal, such as electrodermal activity, may provide additional insight into the brain's functional changes in those with a history of concussion.Objective:To quantify differences in electrodermal activity during a commonly used standardized neurocognitive assessment between individuals with or without a history of concussion.Design:Descriptive laboratory study.Setting:Research laboratory.Patients or Other Participants:Seven asymptomatic individuals with a self-reported history of physician-diagnosed, sport-related concussion (number of previous concussions 1.43 ± 0.53; time since most recent concussion 0.75 to 6 years, median 3 years) and 10 individuals without a history of concussion participated in this study.Main Outcome Measure(s):All participants wore bilateral wrist electrodermal activity sensors during the Standardized Assessment of Concussion. We measured normalized phasic (reactive) electrodermal activity during each test element (orientation, immediate recall, concentration, delayed recall).Results:A significant group-by-test element interaction was present (P .003). Individuals with a history of concussion had greater phasic activity during delayed recall (P< .001). Delayed-recall phasic activity was greater in both groups relative to the other elements.Conclusions:Delayed recall resulted in greater physiologic arousal in previously concussed individuals relative to healthy control participants, supporting previous neuroimaging findings of increased prefrontal cortex activity during memory tasks after concussion. Given similar task performance and arousal patterns across the test, our results suggest that previously concussed individuals incur additional cognitive demands in a short-delay recall task.