Ian Marshall McDonough

Episodic memory is the ability to bind elements of an experience into coherent associations. This ability declines with age, often producing errors that can interfere with daily life. Memory distortions might arise from unstable hippocampal representations that cannot be maintained across encoding, storage, and later retrieval. However, whether aging disrupts the temporal continuity of these representations across memory phases has not been directly tested. Here, adults aged 20–74 completed functional magnetic resonance imaging (fMRI) scanning during an associative memory task involving face–object and face–scene pairings, followed by post-encoding rest and a cued retrieval test. Using multivoxel correlation structure analyses, we quantified hippocampal pattern similarity across each memory stage. Increasing age was associated with increased category errors and reduced representational similarity across all transitions. Higher encoding–retrieval similarity predicted better associative accuracy in younger adults and was less predictive in middle-aged and diminished in older adults. Uniquely among older adults, greater cross-phase similarity predicted elevated category-level binding errors, suggesting a shift from selective reactivation to misbinding with age. Baseline hippocampal organization and encoding-specific connectivity supported accurate reinstatement only in younger adults. Aging disrupts hippocampal stability, possibly representing a core mechanism of age-related decline in associative memory across the adult lifespan.

The same dataset can be analysed in different justifiable ways to answer the same research question, potentially challenging the robustness of empirical science1–3. In this crowd initiative, we investigated the degree to which research findings in the social and behavioural sciences are contingent on analysts’ choices. We examined a stratified random sample of 100 studies published between 2009 and 2018, where for one claim per study, at least five re-analysts independently re-analysed the original data. The statistical appropriateness of the re-analyses was assessed in peer evaluations, and the robustness indicators were inspected along a range of research characteristics and study designs. We found that 34% of the independent re-analyses yielded the same result (within a tolerance region of +/- 0.05 Cohen’s d) as the original report; with a four times broader tolerance region, this indicator rose to 57%. Regarding the conclusions drawn, 74% of analyses were reported to arrive at the same conclusion as in the original investigation; 24% to no effects/inconclusive result, and 2% to the opposite effect as in the original investigation. This exploratory study suggests that the common single-path analyses in social and behavioural research should not simply be assumed to be robust to alternative analyses4. Therefore, we recommend the development and use of practices to explore and communicate this neglected source of uncertainty.

Midlife marks a critical period for detecting Alzheimer's disease (AD) risk because biological and lifestyle factors exceedingly influence brain aging. Konishi et al. used functional magnetic resonance imaging to examine sex differences and risk factors (apolipoprotein E (APOE) ε4, hypertension, type 2 diabetes, depression) on memory-related brain activity starting in midlife. High-risk women showed greater hippocampal hyperactivity, amyloid-β accumulation, and memory deficits than other groups. However, limited sample diversity, lack of tau imaging, unmeasured hormonal levels, and vascular influences constrain interpretations. These findings emphasize the need for sex-informed, mechanistically precise approaches in AD research targeting preclinical stages of disease progression.

Functional magnetic resonance imaging (fMRI) is commonly used to investigate the neural bases of aging and psychological disorders. However, the BOLD signal captured by fMRI is affected by many factors that are non-neural in origin. We tested how vascular health risks, which often go unmeasured in neuroimaging studies, and aging interact to modify the shape and/or timing of the HRF, which then affect the differences in patterns of brain activity in a task-evoked memory encoding paradigm. Adult participants (aged 20–74) answered questions about their health and underwent two fMRI tasks: viewing a flashing checkerboard and a memory encoding task. Aging and vascular risk had the largest impacts on the maximum peak value of the HRF. Using a subject-specific HRF resulted in a dampening of brain activity in task-positive and task-negative regions. Across three vascular risk factors, using a subject-specific HRF resulted in more consistent brain regions that reached significance and larger effect sizes compared with the canonical HRF. These findings serve as a cautious tail when interpreting task-evoked fMRI activity, especially in populations experiencing alterations to brain vasculature including many older adults and people with neurocognitive disorders like Alzheimer’s disease and related dementias.

Background and Objectives: Despite declines in financial ability with age and dementia, research has not explored older adults’ metacognitive awareness of such declines. We investigated the relationship between subjective and objective financial abilities among older adults, and how this relationship changed over 10 years and with cognitive decline. Research Design and Methods: Data from older adults (N = 2,802) in the Advanced Cognitive Training for Independent and Vital Elderly study were used to assess subjective financial performance from the Minimum Data Set for Home Care and objective financial performance from the Everyday Problem Solving Test and the Observed Tasks of Daily Living. Multilevel modeling tested associations between subjective and objective performance and moderating factors. Results: In years when older adults subjectively reported fewer difficulties with their finances, they objectively performed better at financial tasks and this relationship became stronger over 10 years. This relationship was not present for older adults with a dementia diagnosis. Age and objective cognitive impairment did not moderate the relationships. Discussion and Implications: Awareness of financial abilities is critical in an aging population bombarded by fraud and scams. Although older adults without dementia are metacognitively aware of their financial abilities, those diagnosed with dementia are more likely to experience financial anosognosia. These findings offer new insights for programs and early detection tools for dementia.

Episodic memory is a critical cognitive function that enables the encoding, storage, and retrieval of new information. Memory consolidation, a key stage of episodic memory, stabilizes this newly encoded information into long‐lasting brain “storage.” Studies using fMRI to investigate post‐encoding awake rest holds promise to shed light on early, immediate consolidation mechanisms. Here, we review fMRI studies during episodic memory to document common methods to investigate post‐encoding consolidation, such as multivoxel pattern analysis (MVPA) and functional connectivity, and the current state of the science in both healthy younger and older adults. In young adults, post‐encoding reactivation of stimuli‐specific neural patterns in the hippocampus and its connectivity with cortical and subcortical areas (e.g., visual‐temporal cortex, medial prefrontal, and medial parietal cortex) correlate with subsequent memory performance. Conversely, studies in older adults highlight the importance of large‐scale brain networks during post‐encoding rest, particularly the default mode network (DMN). Alterations in connectivity between the DMN and task‐positive networks may help older adults maintain episodic memory. Furthermore, non‐invasive brain stimulation techniques can enhance these post‐encoding consolidation processes and improve memory performance in both younger and older adults. Notably, a lack of studies has investigated post‐encoding memory consolidation in neurodegenerative disorders. This review underscores the importance of understanding how post‐encoding neural reactivation and connectivity evolve with age to partially explain age‐related declines in episodic memory performance and how such declines can be restored.

Cognitive reserve (CR) and busyness can boost memory, whereas stress can impair memory. Nevertheless, extant research has not yet examined busyness in conj

Background: Cadence-controlled walking may be a desirable approach for older adults to self-monitor exercise intensity and achieve physical activity guidelines. We examined the acute effects of cadence-controlled walking on cognition and vascular function in physically inactive older adults. Methods: In a randomized crossover design, 26 participants (65% females, 67.8 ± 11.3 years) underwent 30-min acute exercise (walking at 100 steps/min) and control (sitting) conditions. We measured cognition, central blood pressure (BP), and arterial stiffness before, and immediately, after each condition. Results: We observed significant Time × Condition interactions in the Flanker Inhibitory Control and Attention (Flanker) test and Dimensional Change Card Sort (DCCS) test scores, and in central systolic BP, central pulse pressure, and carotid to femoral pulse wave velocity (p < .05). The Flanker and DCCS scores significantly increased after walking (d = 0.4 and 0.5, respectively), but not after sitting. Central systolic BP, central pulse pressure, and carotid to femoral pulse wave velocity significantly increased after sitting but remained unchanged after acute walking (d = 0.4–0.2), with p-values < .05. After walking, significant correlations were observed between DCCS and diastolic BP and central pulse pressure change scores and change scores in central pulse wave velocity, Flanker, and DCCS (r_s = −0.45 to −0.52). Conclusion: These findings suggest that a single bout of cadence-controlled walking elicited an immediate improvement in cognition and might have mitigated increases in arterial stiffness and central BP observed in the seated control condition. Further research is needed to examine the association between cognition and vascular function following acute exercise compared to control conditions. Significance: Our findings may have practical implications for developing daily physical activity recommendations for improving the cognitive health for successful aging.