This pilot study requests funds to acquire human preliminary data for an NIH Program Project grant to the Aging Institute that plans to combine animal and human imaging techniques to access functional brain baselines during the aging process. The present pilot proposal will aim at demonstrating feasibility for a long-term longitudinal study on normal human brain function during aging. This longitudinal study will utilize electrophysiological functional imaging using magnetoencephalography (MEG) in some cases combined with MRI imaging. The main thrust will be to establish top-down / bottom up activity as part of thalamo-cortical baseline dynamics and their changes with age. We have reasons to propose that the intellectual slowing, characteristic of the aging process, is in part a circuit timing problem due to altered synchronization and coherence during cognitive tasks. In this pilot study we aim at acquiring preliminary MEG data during early sensory processing and during visual cognitive memory tasks. The MEG analysis will use new techniques that address frequency domain, as well as time domain, signals. Our working hypothesis is that although sensory processing is achieved by dedicated units, the cognitive binding process is a common mechanism across modalities. More over, it is proposed that such time dependent binding when altered, will result in modifications of sensory motor integration that will affect cognition in the aging brain. This hypothesis will be tested by magnetoencephalographic means using different types of sensory stimuli in healthy young and older subjects.
