Exercise Training and Functional Connectivity Changes in Mild Cognitive Empairment and Healthy Elders

Background: Effective interventions are needed to improve brain function in mild cognitive impairment (MCI), an early stage of Alzheimer’s disease (AD). The posterior cingulate cortex (PCC)/precuneus is a hub of the default mode network (DMN) and is preferentially vulnerable to disruption of functional connectivity in MCI and AD. Objective: We investigated whether 12 weeks of aerobic exercise could enhance functional connectivity of the PCC/precuneus in MCI and healthy elders. Methods: Sixteen MCI and 16 healthy elders (age range = 60–88) engaged in a supervised 12-week walking exercise intervention. Functional MRI was acquired at rest; the PCC/precuneus was used as a seed for correlated brain activity maps. Results: A linear mixed effects model revealed a significant interaction in the right parietal lobe: the MCI group showed increased connectivity while the healthy elders showed decreased connectivity. In addition, both groups showed increased connectivity with the left postcentral gyrus. Comparing pre to post intervention changes within each group, the MCI group showed increased connectivity in 10 regions spanning frontal, parietal, temporal and insular lobes, and the cerebellum. Healthy elders did not demonstrate any significant connectivity changes. Conclusion: The observed results show increased functional connectivity of the PCC/precuneus in individuals with MCI after 12 weeks of moderate intensity walking exercise training. The protective effects of exercise training on cognition may be realized through the enhancement of neural recruitment mechanisms, which may possibly increase cognitive reserve. Whether these effects of exercise training may delay further cognitive decline in patients diagnosed with MCI remains to be demonstrated

Driving performance in older adults: Current measures, findings, and implications for roadway safety

BACKGROUND AND OBJECTIVES: Over 10,000 people a day turn 65 in the United States. For many older adults, driving represents an essential component of independence and is one of the most important factors in overall mobility. Recent survey studies in older adults suggest that up to 60% of older adult drivers with mild cognitive impairment, and up to 30% with dementia, continue to drive. The purpose of this review is to provide a comprehensive and detailed resource on the topics of cognition and driving for clinicians, researchers, and policymakers working on efforts related to older adult drivers. RESEARCH DESIGN AND METHODS: Publications on PubMed and Medline and discussions with experts working in geriatrics, technology, driving policy, psychology, and diverse aspects of driving performance were utilized to inform the current review. RESULTS: Research indicates that there is a complex and inverse correlation between multiple cognitive measures, driving performance, and risky driving behaviors. The fragmented nature of available peer-reviewed literature, and a reliance on correlative data, do not currently allow for the identification of the temporal and reciprocal nature of the interplay between cognition and driving endpoints. DISCUSSION AND IMPLICATIONS: There are currently no widely accepted definitions, conceptual models, or uniform set of analyses for conducting geriatric research that is focused on driving. Establishing conventions for conducting research that harmonizes the fields of geriatrics, cognition, and driving research is critical for the development of the evidence base that will inform clinical practice and road safety policy

Can a Smartphone Application Be Used to Measure Practice Driving Behavior During the Learner Permit Period? A Step Toward Performance-Based Licensing

Introduction: Supervised practice during the learner stage of graduated driver licensing is required in all U.S. states and some international jurisdictions. Several U.S. states require driving hours to be recorded in a paper logbook, making it susceptible to errors or falsification. A smartphone app that operates as an electronic logbook could serve as an alternative. The purpose of this study was to measure the impact of the logbook format (i.e., paper versus electronic) on self-reported driving behavior. Design: Parent‒teen dyads were enrolled and assigned to electronic (n=147) and paper (n=131) logbook groups using a block design. Setting/Participants: This study was conducted in Maryland. Data were collected for 6 continuous months while teenagers held a learner permit between January 2020 and December 2021. Intervention: Electronic logbook to measure practice driving. Outcome measure: Self-reported driving between the electronic and paper logbook groups. For those using electronic logbooks, an agreement between self-reported trips and electronic logbook trips and perceptions of using an electronic logbook to measure driving. Results: There were no statistically significant differences in any measures of self-reported practice driving by logbook type (electronic versus paper). Agreement between self-reported and electronic logbook‒recorded trips ranged between 68.6% and 79.0% (allowing a difference of 2 trips per week). User satisfaction with the electronic logbook was high, with 93.0% of teenagers and 91.9% of parents stating that they would recommend the app to a friend. Conclusions: An electronic logbook is a viable approach to measuring practice driving. Eventually, it could become part of a system where practice requirements are verified, allowing states to move toward performance-based graduated driver licensing

Striatal bases of temporal discounting in early adolescents

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.Steeper rates of temporal discounting—the degree to which smaller-sooner (SS) rewards are preferred over larger-later (LL) ones—have been associated with impulsive and ill-advised behaviors in adolescence. Yet, the underlying neural systems remain poorly understood. Here we used a well-established temporal discounting paradigm and functional MRI (fMRI) to examine engagement of the striatum—including the caudate, putamen, and ventral striatum (VS)—in early adolescence (13–15 years; N=27). Analyses provided evidence of enhanced activity in the caudate and VS during impulsive choice. Exploratory analyses revealed that trait impulsivity was associated with heightened putamen activity during impulsive choices. A more nuanced pattern was evident in the cortex, with the dorsolateral prefrontal cortex mirroring the putamen and posterior parietal cortex showing the reverse association. Taken together, these observations provide an important first glimpse at the distributed neural systems underlying economic choice and trait-like individual differences in impulsivity in the early years of adolescence, setting the stage for prospective-longitudinal and intervention research.NIH R00DA038589NIH DA040717NIH MH10744