Age-related changes in brain–behaviour relationships: Evidence from event-related functional MRI studies Bart Rypma and Mark D’Esposito University of California, Berkeley, USA A fundamental aim of studies in neurocognitive ageing is to understand age-related changes in brain–behaviour relationships. Neuroimaging techni- ques such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) can be used for observation of these age-related changes only if the assumption of age-equivalent relations between neural activity and haemodynamic activity is valid. In one study, we characterised age-related diVerences in the coupling of the haemodynamic response to neural activity and found greater voxel-wise noise in older than in younger adults, but age-equivalent signal magnitude. These results suggested that alternative techniques may be necessary for analysing age-related diVerences in neuroimaging data. In a second study, we utilised one alternative method for comparing fMRI activation between younger and older adults performing a working memory (WM) task. Across three experiments, the results suggested that age-related functional changes in fMRI activation can be isolated to dorsolateral prefrontal cortex (PFC) during memory retrieval. These results suggest a plausible model for WM decline with normal ageing. In a third study we propose and test a model of age-related PFC dysfunc- tion that may account for these and other age-related diVerences in cogni- tive performance. A fundamental aim of studies in neurocognitive ageing is to understand how the ageing brain mediates age-related changes in the performance of cognitive tasks. The advent of neuroimaging techniques such as PET and fMRI permits more direct observation of these age-associated changes in the brain than has been possible in the past. Thus, hypotheses developed through behavioural comparisons of younger and older adults, and older Requests for reprints should be addressed to B. Rypma, Department of Psychology, University of California, 3210 Tolman Hall, Berkeley, CA 94720-1650, USA. Email: rypma@socrates.berkley.edu Supported by the American Federation for Aging Research and NIH grants NS01762, AG13483 and AG15793.  2001 Psychology Press Ltd http:// www.tandf.co.uk/journals/ pp/ 09541446.html DOI:10.1080 / 09541440042000296 EUROPEAN JOURNAL OF COGNITIVE PSYCHOLOGY, 2001, 13 (1/ 2), 235–256