Magnesium is an essential nutrient involved in a wide range of physiological activities to maintain normal brain functions. So far, magnesium has been recognized as a cofactor for over 600 enzymatic reactions within the body. Importantly, magnesium deficiency has been implicated in the pathogenesis of various dementia-related diseases containing cardiovascular diseases and Alzheimer’s disease (AD). With increased aging, the incidence and prevalence of dementia are expected to rise dramatically double every 20 years worldwide. Accumulating evidence indicates that dementia-related diseases are associated with low magnesium levels, and dietary magnesium intake can improve cognitive function. Many studies have revealed that magnesium ions act as a natural Ca²⁺ blocker to inhibit calcium overload and halt the course of AD by blocking N-methyl-D-aspartate receptors and thus inhibiting neuronal overactivation. In addition, magnesium ions can inhibit glial cell-mediated neuroinflammation by down-regulating pro-inflammatory cytokines and oxidative stress, which have been implicated in the development of chronic age-related diseases. Thus, magnesium may be a target for the prevention and treatment of neurological diseases. Taken together, maintaining an optimal magnesium balance may help in the prevention of cognitive decline and dementia. In this review, we summarize our current understanding of the role of magnesium in dementia, highlighting recent progresses in the field.

Top-down attention mechanisms require the selection of specific objects or locations; however, the brain mechanism involved when attention is allocated across different modalities is not well understood. The aim of this study was to use functional magnetic resonance imaging to define the neural mechanisms underlying divided and selective spatial attention. A concurrent audiovisual stimulus was used, and subjects were prompted to focus on a visual, auditory and audiovisual stimulus in a Posner paradigm. Our behavioral results confirmed the better performance of selective attention compared to devided attention. We found differences in the activation level of the frontoparietal network, visual/auditory cortex, the putamen and the salience network under different attention conditions. We further used Granger causality (GC) to explore effective connectivity differences between tasks. Differences in GC connectivity between visual and auditory selective tasks reflected the visual dominance effect under spatial attention. In addition, our results supported the role of the putamen in redistributing attention and the functional separation of the salience network. In summary, we explored the audiovisual top-down allocation of attention and observed the differences in neural mechanisms under endogenous attention modes, which revealed the differences in cross-modal expression in visual and auditory attention under attentional modulation.