Time Slows Down in the Future: Aging and the Brain Rhythms of Language.

Abstract

Language is perhaps the most complex and sophisticated of cognitive faculties in humans. The neurobiological basis of language in the healthy, aging brain remains a relatively neglected topic, in particular with respect to basic aspects of grammar and meaning. In the face of major changes to the physiological infrastructure underpinning perception and higher cognition, core language functions are frequently retained in the elderly. Meanwhile, neurolinguistic models of language are often tested and refined with reference to system abnormalities (as in cases of language deficits or aphasias), but rarely with reference to the aging brain. This article outlines some major developmental stages in the neural architecture of language, and reviews the current state-of-the-art in research concerning how aging can result in distinct neural signatures of language. Certain differences in basic phrase and sentence processing strategies between children, young adults, and older adults can partly be explained by neurophysiological differences, and also divergences in core components of brain rhythms. Particular focus is placed here on spatiotemporal dynamics and neural oscillations, inter-brain coupling, 1/f neural noise, and neural entrainment. Exploring how language function changes with age can ultimately provide insights into the maturation and decay of basic properties of cortical computation.