Neurocognitive ageing of storage and executive processes

Converging behavioural and neuropsychological evidence indicates that age-r elated changes in working memory contribute substantially to cognitive decl ine in older adults. Important questions remain about the relationship betw een working memory storage and executive components and how they are affect ed by the normal ageing process. In several studies using positron emission tomography (PET), we find age differences in the patterns of frontal activ ation during working memory tasks. We find that separable age differences c an be linked to different cognitive operations underlying short-term inform ation storage, and interference resolution. Some operations are associated with age-related increases in activation, with older adults displaying bila teral activations and recruiting prefrontal areas more than younger adults. Other operations are associated with age-related decreases in activation. We consider the implications of these results for understanding the working memory system and potential compensatory processes in the ageing brain.