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キーワード:
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要旨:
Whether it is a pleasant dinner or a dream vacation, having something to look forward to is a
keystone in building a happy life. Recent studies suggest that reward prediction errors can enhance the
pleasure of anticipation. This enhanced anticipation is linked to why people seek information that cannot be
acted upon, and is potentially associated with a vulnerability to addiction. However, the neural roots of the pleasure from anticipation are largely unknown. To address this issue, we studied how the brain generates
and enhances anticipation, by exposing human participants to a delayed reward decision-making task while
imaging their brain activities. Using a computational model of anticipation, we identified a novel anticipatory
network consisting of three regions. We found that the ventromedial prefrontal cortex (vmPFC) tracked
an anticipation signal, while dopaminergic midbrain responded to an unexpectedly good forecast. We found
that hippocampus was coupled both to the vmPFC and to the dopaminergic midbrain, through the model’s
computation for boosting anticipation. This result suggests that people might experience greater anticipation
when vividly imagining future outcomes. Thus, our findings propose a cognitive circuit for anticipatory
value computation, unifying interpretations of separate notions such as risk and delay preference. Our study
opens up a new avenue to understanding complex human decisions that are driven by reward anticipation,
rather than well-studied reward consumption, and offers a novel intervention target for psychiatric disorders
that involve motivation and future rewards.
