|Reference code: ||PT/FB/BL-2006-061.02|
|Location: ||Arquivo PCA - Pasta 4/2006|
|Neural mechanisms of temporal discounting|
|Publication year: ||2010|
Temporal discounting refers to the decrease in subjective value as a result of delay of reward. Previous studies have focused on neural correlates of intertemporal choice, e.g. decisions between $10 today and $11 tomorrow. This approach makes it difficult to isolate neural correlates of individual delayed rewards, and to dissociate neural correlates of valuation from decision processes. The present study attempts to identify
the neural correlates of temporal discounting per se, as distinct from intertemporal choices.
Subjects were presented with single rewards of varying magnitude and delay, allowing us to identify neural correlates of temporally discounted value without confounds from decision processes. In addition, we could dissociate representations of valence vs. arousal due to the inclusion of both positive and negative payoffs.
We find that delay of reward is reflected in the caudate nucleus and nucleus accumbens, where activation increases going from long to short delays for gains, and decreases from long to short delays for losses. In addition, the steepness of the neural discount function in caudate nucleus correlated with individual discount parameters obtained in a separate testing session. Conversely, reward magnitude is most strongly reflected in nucleus accumbens, where activation increases from small to large gains and from large to small losses.
Together, our results demonstrate that caudate nucleus represents temporally discounted value, independently of decision processes and arousal, and in a manner that reflects subjective time preferences. More generally, our study shows that limbic regions can encode abstract features of a reward, such as delay.
|Accessibility: ||Document does not exist in file|
|Secondary author(s): |
|Kanwisher, N., Haushofer, J., Libedinsky, C.|
|Document type: |
|Livingstone, M., Kanwisher, N., Haushofer, J., & Libedinsky, C. (2010). Neural mechanisms of temporal discounting. In Aquém e além do cérebro. Behind and beyond the brain. Proceedings of the 8th Symposium of Fundação Bial (p. 213). Porto: Fundação Bial.|
|Indexed document: ||No|
|Keywords: ||Temporal discounting / Reward / Neuroeconomics / Functional magnetic resonance imaging (fMRI)|
Neural mechanisms of temporal discounting