Healthy aging attenuates task-related specialization in the human medial temporal lobe

Thomas Z. Ramsøy, Matthew George Liptrot, Arnold Jesper Møller Skimminge, Torben E. Lund, Karam Sidaros, Mark Schram Christensen, William Baaré, Olaf B. Paulson, Terry L. Jernigan, Hartwig R. Siebner

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    Recent research on aging has established important links between the neurobiology of normal aging and age-related decline in episodic memory, yet the exact nature of this relationship is still unknown. Functional neuroimaging of regions such as the medial temporal lobe (MTL) have produced conflicting findings. Using functional magnetic resonance imaging (fMRI), we have recently shown that young healthy individuals show a stronger activation of the MTL during encoding of objects as compared with encoding of positions. Using the same encoding task, the present study addressed the question whether this greater MTL activation during encoding of objects varies with age. Fifty-four healthy individuals aged between 18 and 81 years underwent functional magnetic resonance imaging while they encoded and subsequently made new-old judgments on objects and positions. Region of interest (ROI) analysis of task related changes in the blood oxygen level-dependent (BOLD) signal was performed in native space after correction for gender effects and individual differences in cerebral blood flow. The hippocampus, amygdala, and parahippocampal, perirhinal, entorhinal, and temporopolar cortices of right and left hemisphere were defined as ROIs. Aging had an adverse effect on memory performance that was similar for memorizing objects or positions. In left and right MTL, relatively greater activation for object stimuli was attenuated in older individuals. Age-related attenuation in content specificity was most prominent in the recognition stage. During recognition, the larger response to objects gradually decreased with age in all ROIs apart from left temporopolar and entorhinal cortex. An age-related attenuation was also present during encoding, but only in right parahippocampus and amygdala. Our results suggest that memory-related processing in the MTL becomes gradually less sensitive to content during normal aging.
    Original languageEnglish
    JournalNeurobiology of Aging
    Volume33
    Issue number9
    Pages (from-to)1874-1889
    ISSN0197-4580
    DOIs
    Publication statusPublished - 2012

    Keywords

    • Aging
    • Episodic memory
    • Encoding
    • Specialization
    • Recognition
    • Neural specificity
    • Working memory

    Fingerprint

    Dive into the research topics of 'Healthy aging attenuates task-related specialization in the human medial temporal lobe'. Together they form a unique fingerprint.

    Cite this