The Effects of Normal Aging on Cortical Inhibition Function---A Comprehensive Study by Using Magnetoencephalography, Magnetic Resonance Spectroscopy and Behavioral Approaches

Several lines of evidence have shown that aging affects cognitive operations, including attention, memory, and executive function. Among these higher-order cerebral processes, inhibition function (or inhibition mechanism) exerts an essential and significant role. It has been reported that decline of aging-related working memory is due to a suppression deficit in task-irrelevant representation, whereas task-related brain activity is relatively preserved. By using magnetic resonance spectroscopy (MRS), previous studies have demonstrated an association between resting γ-aminobutyric acid (GABA) concentration and peak frequency of stimulus-induced gamma oscillation in the human visual cortex. The neurotransmitter of GABA and brain oscillation of gamma bands participate in the different hierarchical levels of inhibition function. However, exception for the visual cortex, the profile of inhibition mechanism in other sensory regions, such as auditory and somatosensory cortices, remains largely unknown. Moreover, the effects of aging, which influences inhibition control a great deal, on this fundamental function are extremely uncertain. Thus, the present study aims 1) to use non-invasive MRS, magnetoencephalography (MEG), and behavioral tasks to examine the relationship among resting GABA concentration, stimulus-induced gamma oscillation, abd behavioral performance in human auditory and somatosensory cortices, and 2) to investigate whether aging processes modulate any factor mentioned above. The novelty of this study is that it comprehensively evaluate the neurotransmitter, brain oscillation, and behavioral parameters at the same timeline to understand the aging-related effects on the inhibition function at different hierarchical scopes. In the first year, we will recruit young healthy adults and establish a solid, reliable experimental procedure, including data acquisition, parameter settings, and analysis pipeline. In the second year, we will invite older healthy adults to participate in this study and try to clarify the aging-related alterations in terms of cortical and behavioral inhibition function. It is hoped that the expected findings could provide a reference frame for future studies on normal aging or neurodegenerative diseases.

Project ID:PC10501-1720
External Project ID:MOST104-2314-B182-001-MY2