Electrophysiological and Optical Measures of Cognitive Aging

This chapter reviews optical brain imaging and electrophysiology in the context of other available methodologies as they apply to aging research. Both methods emphasize the temporal aspects of the brain phenomena underlying cognition and thus allow for a closer parallel with cognitive studies using a mental chronometry approach to the study of aging. However, these two methods differ in the amount of localization information they provide, with electrophysiological methods yielding a coarser spatial description of brain activity and optical imaging meshing temporal and spatial information at a finer level. The spatial resolution of optical imaging may be close to that reached with functional magnetic resonance imaging (fMRI) or positron emission tomography (PET), especially when data from a number of subjects are combined, which leads to a loss of resolution for all techniques.