ABSTRACT
As described in the previous chapter, a commonly used marker of abnormality
in EEG studies of AD is EEG slowing , which quantifies the impairment of
the temporal or the frequency aspect of the information processing ability
of the brain. Reduced values of similarity measures such as coherence (or
correlation) (Besthorn et al., 1994; Locatelli et al., 1998; Stevens et al., 2001;
Jeong, 2004) and mutual information (Jeong et al., 2001b) between EEGs
recorded from various regions of the brain have also been proposed as potential
markers of abnormality. These quantify the impairment of the corticocortical
connectivity or the spatial aspect of the information processing ability of the
brain which involves the proper assimilation of information by various brain
regions. Together, the spatio-temporal impairment of information processing
in the brain can be correlated to the symptoms of memory loss and cognitive
impairment in AD.
