Functional dedifferentiation and reduced task-related deactivations underlie the age-related decline of prospective memory
Résumé
Prospective memory (PM) refers to the ability to remember to execute an intention at
the appropriate moment in the future, which can be performed either at the appearance of an
event (event-based, EBPM) or after a certain amount of time (time-based, TBPM). PM is
generally impaired during aging but the cerebral substrates of this decline have been little
investigated. Using functional Magnetic Resonance Imaging (fMRI), we investigated the
neural bases of PM in 20 young and 20 healthy older adults. They were proposed a task of
semantic categorisation of pictures (ongoing task). For some blocks, participants only had to
perform this ongoing task while, for others, a PM instruction was added. In this case, a
supplementary answer in response to a specific colour of border for EBPM or at specific time
intervals for TBPM was expected. PM, and more particularly TBPM, declined in older adults.
For both PM conditions, older adults recruited additional brain areas, but also showed
reduced deactivations of other regions. These results are discussed in light of models of the
aging brain.
Domaines
Neurosciences [q-bio.NC]
Origine : Fichiers produits par l'(les) auteur(s)
Loading...