For cognitive tests we used completion time on Trail Making Test A and B. Performance on these tests has been associated with key cognitive functions, including cognitive control processes, working memory and perceptual speed3738. All these measures have been shown to be negatively affected by age1132330 and to be modulated by neural activity in the delta and theta range274041424344. Thus, of particular interest in the current study was to explore the associations between slow wave spectral power and performance on these tests across the life-span.
