The utility of measures of electrophysiological and information processing variability in distinguishing between normal age-related cognitive decline, Subjective Memory Complaint (SMC), Mild Cognitive Impairment (MCI), and Alzheimer's disease (AD)

  • Michael Hogan1,

    Affiliated with

    • Richard Roche2,

      Affiliated with

      • Paul Dockree2,

        Affiliated with

        • Ian Robertson2 and

          Affiliated with

          • Brian Lawlor2

            Affiliated with

            Annals of General Psychiatry20065(Suppl 1):S214

            DOI: 10.1186/1744-859X-5-S1-S214

            Published: 28 February 2006


            Recent theoretical models of cognitive aging have implicated increased intra-individual variability as a critical marker of decline. The current study examined electrophysiological and information processing variability and memory performance in normal younger and older adults, and older adults with Subjective Memory Complaint (SMC), Mild Cognitive Impairment (MCI), and Alzheimer's Disease (AD). It was hypothesized that higher levels of variability would be indicative of age-related and disease-related memory deficits.

            Materials and methods

            24 young, 24 old, 21 SMCs, 15 MCIs, and 16 ADs (Mean age = 21.5, 72.8, 71.8, 76, and 77 years, respectively) were recruited with informed consent and received clinical assessment (Hogan et al., 2003), neuropsychological screening, and electrophysiological assessment while performing an implicit and explicit memory task.


            Consistent with previous research, behavioural variability emerged as sensitive to age- and disease-related change. Results also indicated that amplitude variability (AmpV) of event-related potentials (ERPs) provide some additional insight into the dynamic nature of age- and disease-related memory changes.


            Results are discussed in light of theoretical and applied issues in the field of cognitive aging.

            Authors’ Affiliations

            Trinity College


            1. Hogan MJ, Swanwick GR, Kaiser J, Rowan M, Lawlor B: Memory-related EEG power and coherence reductions in mild Alzheimer's disease. Int J Psychophysiol. 2003, 49: 147-163. 10.1016/S0167-8760(03)00118-1.View ArticlePubMed


            © The Author(s) 2006