Mechanisms and outcomes of flipped music education: a conceptual framework linking self-directed learning, collaboration, and student wellbeing.

As the global population ages, the number of adults aged ≥ 65 years is projected to more than double from 761 million in 2021 to 1.6 billion by 2050, accompanied by a steep rise in dementia prevalence. With no cure currently available, there is an urgent need to better understand the intersecting factors (i.e., sex, ethnicity, and lifestyle) that shape brain and cognitive aging across individuals. Rates of age‐associated cognitive decline vary by sex and ethnicity, although findings are inconsistent., Physical activity (PA) is a highly impactful lifestyle factor that influences cognitive aging, particularly in females; the role of ethnicity in these relationships is largely overlooked and remains poorly understood. Blood biomarkers offer valuable insight into the processes underlying cognitive aging and dementia risk. Circulating levels of markers such as amyloid beta (Aβ40, Aβ42), neurofilament light chain (NfL), and total tau capture complementary aspects of neuropathology, including amyloid deposition, axonal injury, and tau‐related neurodegeneration. Some studies have found no sex differences in Aβ burden in cognitively normal older adults, while others have reported higher levels of cerebral amyloid angiopathy in males than in females., Higher tau levels in females are more consistently found across populations, including in cognitively unimpaired individuals, in mild cognitive impairment, and in dementia. Across studies and systematic reviews, engagement in regular PA slows age‐related cognitive decline and promotes cognition, with some studies beginning to show reduced neurodegeneration., Biological sex seems to influence the type and extent of cognitive benefits derived from PA and exercise. For example, maintenance of PA was associated with less decline in executive functions and greater volume of the dorsolateral prefrontal cortex (DLPFC), the brain area that subserves executive functions,, in older females but not older males. Higher PA also seems to impact the hippocampus, which is involved in episodic memory, though the direction of the relationship may be sex dependent. Moreover, evidence from rodent studies indicates that PA induces increases in the production of new neurons within the hippocampus., , Whether the sex difference extends to other cognitive domains and underlying brain structures, is seen across ethnicities, and is reflected in reductions in neurodegeneration biomarkers is not known. Therefore, the current investigation sought to: (1) examine the impact of biological sex and ethnicity on the cross‐sectional relationship between PA and cognition in older adults and (2) investigate the potential underlying mechanisms with a focus on blood‐based biomarkers, hippocampal and subregion volumes, and DLPFC thickness.