摘要：Aging is associated with structural and functional brain changes which may impact
the regulation of motivated behaviors, including both action and inhibition of action.
As behavioral regulation is often exercised in response to reward, it remains unclear
how aging may influence reward-directed action and inhibition of action differently. Here
we addressed this issue with the functional magnetic resonance imaging data of 72
participants (aged 21–74) performing a reward go/no-go (GNG) task with approximately
2/3 go and 1/3 no-go trials. The go and no-go success trials were rewarded with a
dollar or a nickel, and the incorrect responses were penalized. An additional block of the
GNG task without reward/punishment served as the control to account for age-related
slowing in processing speed. The results showed a prolonged response time (RT) in
rewarded (vs. control) go trials with increasing age. Whole-brain multiple regressions
of rewarded (vs. control) go trials against age and RT both revealed an age-related
reduced activity of the anterior insula, middle frontal gyrus, and rostral anterior cingulate
cortex. Furthermore, activity from these regions mediated the relationship between age
and go performance. During rewarded (vs. control) no-go trials, age was associated
with increased accuracy rate but decreased activation in the medial superior frontal and
postcentral gyri. As these regions also exhibited age-related activity reduction during
rewarded go, the finding suggests aging effects on common brain substrates that
regulate both action and action inhibition. Taken together, age shows a broad negative
modulation on neural activations but differential effects on performance during rewarded
action and inhibition of action.
关键词：Aging; action; inhibition of action; Reward; fMRI; go/no-go
