Figural memory performance and fMRI activity across the adult lifespan

Abstract

We examined performance and fMRI activity in participants (n=235) aged 17-81yrs on a non-verbal recognition memory task, figural memory. Reaction time, error rate and response bias measures indicated that the youngest and oldest participants were faster, made fewer errors and showed a more conservative response bias than participants in the median age ranges. Encoding and Recognition phases activated a distributed bilateral network encompassing prefrontal, subcortical, lateral and medial temporal and occipital regions. Activation during Encoding phase did not correlate with age. During Recognition, task-related activation for correctly identified targets (Hit-Targets) correlated linearly positively with age; non-task related activity correlated negative quadratically with age. During correctly identified distractors (Hit-Distractors) activity in task-related regions correlated positive linearly with age, non-task activity showed positive and negative quadratic relationships with age. Missed-Targets activity did not correlate with age. We concluded that figural memory performance and fMRI activity during Recognition but not Encoding was affected both by continued maturation of the brain in the early 20s and compensatory recruitment of additional brain regions during recognition memory in oldage.