Cardiorespiratory fitness is associated with cognitive performance in 80 + -year-olds: Detangling processing levels.

Cardiorespiratory fitness is known to protect against cognitive decline in older adults. Specifically, it has been shown that physical activity and fitness are beneficial for executive functions that are crucial for independent living up to old age. In this study, 115 individuals aged 80 years and older underwent a cardiorespiratory fitness assessment using the two-minute step test and had their electroencephalogram recorded during a colored flanker task in order to measure executive function performance. Cardiorespiratory fitness was related to quicker responses during the flanker task. A mediation analysis was carried out to determine whether these positive effects were mediated through event-related potentials (N1, N2, or P3) or motor-related cortical potentials (MRCP). Cardiorespiratory fitness was related to better visual discriminative processing as indicated by larger occipital N1 amplitudes. In addition, fitness was associated with larger MRCP amplitudes, which are a correlate of the response generation process. Fitness was not found to have a significant effect on fronto-central N2 or parietal P3, which are thought to capture cognitive control processes such as conflict detection and response inhibition. Moreover, all effects reported were present in all three flanker trial conditions (congruent, neutral, and incongruent). Thus, these results indicate that the quicker response times in fitter people were related to visual processing and motor response generation rather than cognitive control.