AUTHOR=Hoppstädter Michael , King Andrea V., Frölich Lutz , Wessa Michèle , Flor Herta , Meyer Patric TITLE=A combined electrophysiological and morphological examination of episodic memory decline in amnestic mild cognitive impairment JOURNAL=Frontiers in Aging Neuroscience VOLUME=5 YEAR=2013 URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2013.00051 DOI=10.3389/fnagi.2013.00051 ISSN=1663-4365 ABSTRACT=

Early stages of Alzheimer’s disease (AD) are characterized by neuropathological changes within the medial temporal lobe cortex (MTLC), which lead to characteristic impairments in episodic memory, i.e., amnestic mild cognitive impairment (aMCI). Here, we tested the neural correlates of this memory impairment using event-related potentials (ERPs) and voxel-based morphometry. Twenty-four participants were instructed to encode lists of words and were tested in a yes/no recognition memory task. The dual-process model of recognition memory dissociates between acontextual familiarity and recollection of contextual details. The early frontal ERP old/new effect, which is thought to represent a neural correlate of familiarity-based memory, was absent in aMCI, whereas the control group showed a significant early old/new effect at frontal electrodes. This effect was positively correlated with behavioral episodic memory performance. Analyses of brain morphology revealed a focused gray matter loss in the inferior and medial temporal lobes in aMCI versus healthy controls. Moreover, the positive correlation between gray matter volume in the MTLC and the familiarity-related early frontal old/new effect supports the notion that this effect relies upon the integrity of the MTLC. Thus, the present findings might provide a further functional marker for prodromal AD.