Studies focusing on pathological aging generally agree that enhanced slow wave spectral activity is associated with cognitive impairment (e.g.333536). For example, Fernández et al.33 reported enhanced theta/delta dipole density on AD patients compared to healthy controls, associated with deficient neurocognitive functioning. Grunwald and colleagues3536 correlated theta power from seniors with different stages of cognitive impairment (forming a continuum from healthy to demented subjects) with hippocampal volume and found significant negative linear associations, suggesting that the observed slow wave alterations in the cortex may be accounted for by the neuronal loss in the hippocampus.
