Age-related changes in regional activation during working memory in young adults: An fMRI study

Several lines of evidence suggest that working memory diminishes with advan cing age, with concomitant functional changes in associated neuronal activa tion in frontal cortical regions and hippocampi. No studies to date, howeve r, have investigated age-related changes in neuronal activation in these re gions during performance of a working memory task in younger subjects witho ut working memory deficits. In this study, we utilized fMRI to examine chan ges in brain activation with increasing age in specific regions-of-interest . Eleven healthy subjects performed a "two-back" working memory task and a matched "zero-back" attention task during fMRI. There was no association be tween age and performance on either task. Left hippocampal activation signi ficantly correlated with age (P = 0.01) and right hippocampal activation sh owed an association with age (P = 0.09). This study demonstrates that incre asing age is associated with increased activation of hippocampus even in yo ung patients without evidence of working memory deficits and suggests that functional changes may precede overt evidence of working memory deficits. ( C) 2001 Wiley-Liss, Inc.