How does Sato assess changes in cognitive functioning over a lifespan?

Sato's approach to assessing changes in cognitive functioning over a lifespan is rooted in the methodology of longitudinal studies that track cognitive performance over time. Longitudinal studies involve repeated observations of the same variables – in this case, cognitive functions – over an extended period. This method allows researchers to detect changes and trends in cognitive abilities as individuals age, providing a clearer understanding of how cognitive functioning evolves throughout different life stages.

By following the same group of individuals, Sato can take into account intra-individual variability and the impacts of life experiences on cognitive change. This method far surpasses a snapshot in time that cross-sectional studies provide, where different age groups are compared without controlling for individual developmental trajectories. Longitudinal studies offer deeper insights into causation and developmental patterns, crucial for understanding cognitive aging accurately.

In contrast, the other options provide less effective means of studying cognitive changes. Cross-sectional studies lack the depth needed for understanding changes over time, surveys can be limited in their comprehensiveness and often rely on self-reported data, and focusing solely on young adults overlooks the full spectrum of cognitive development and decline throughout the lifespan.