PET insights into the neural correlates of working memory

Brisbane Convention & Exhibition Centre 

In this talk, I will present findings from two studies using multi-modal imaging to investigate age-related changes in brain activation during working memory tasks. The first study acquired simultaneous PET with [18F]fluoro-deoxyglucose and fMRI in young and older adults. We show that while task-induced BOLD and glucose metabolism generally converged, activation increases in older adults lacked corresponding increases in metabolic activity, suggesting they are not directly reflective of synaptic activity. A follow -up study that combined fMRI with PET dopamine receptor imaging suggests reduced dopamine receptor density as a mechanism underlying age-related differences in the BOLD response outside a canonical working memory network. Together, they highlight the power of PET to aid the interpretation of task-fMRI responses