Datensatz

Zusammenfassung

A number of recent functional Magnetic Resonance Imaging (fMRI) studies on intertemporal choice behavior have
demonstrated that so-called emotion- and reward-related brain areas are preferentially activated by decisions
involving immediately available (but smaller) rewards as compared to (larger) delayed rewards. This pattern of
activation was not seen, however, when intertemporal choices were made for another (unknown) individual, which
speaks to that activation having been triggered by self-relatedness. In the present fMRI study, we investigated the
brain correlates of individuals who passively
observed
intertemporal choices being made either for themselves or for
an unknown person. We found higher activation within the ventral striatum, medial prefrontal and orbitofrontal cortex,
pregenual anterior cingulate cortex, and posterior cingulate cortex when an immediate reward was possible for the
observer herself, which is in line with findings from studies in which individuals actively
chose
immediately available
rewards. Additionally, activation in the dorsal anterior cingulate cortex, posterior cingulate cortex, and precuneus was
higher for choices that included immediate options than for choices that offered only delayed options, irrespective of
who was to be the beneficiary. These results indicate that (1) the activations found in active intertemporal decision
making are also present when the same decisions are merely observed, thus supporting the assumption that a robust
brain network is engaged in immediate gratification; and (2) with immediate rewards, certain brain areas are activated
irrespective of whether the observer or another person is the beneficiary of a decision, suggesting that immediacy
plays a more general role for neural activation. An explorative analysis of participants’ brain activation corresponding
to chosen rewards, further indicates that activation in the aforementioned brain areas depends on the mere
presence, availability, or actual reception of immediate rewards.