Reliable differences in brain activity between young and old adults: A quantitative meta-analysis across multiple cognitive domains

We conducted a systematic review of the neuroimaging literature examining cognition in old and young adults and quantified these findings in a series of meta-analyses using the activation likelihood estimation technique. In 80 independent samples, we assessed significant convergent and divergent patterns of brain activity across all studies; where task performance was equated or different between age groups; and in four specific cognitive domains (perception, memory encoding, memory retrieval and executive function). Age differences across studies predominantly involved regions within the 'task-positive network' of the brain, a set of interconnected regions engaged during a variety of externally driven cognitive tasks. Old adults engaged prefrontal regions more than young adults. When performance was equivalent, old adults engaged left prefrontal cortex; poorly performing old adults engaged right prefrontal cortex. Young adults engaged occipital regions more than old adults, particularly when performance was unequal and during perceptual tasks. No age-related differences were found in the parietal lobes. We discuss the reliable differences in brain activation with regards to current theories of neurocognitive aging. (C) 2010 Elsevier Ltd. All rights reserved.