Shohamy and colleagues found that administration of a placebo can enhance learning from positive outcomes in Parkinson disease's patients. An analysis of fMRI signals recorded during behavior indicated that the drug and placebo both enhanced the representation of expected value in the ventromedial prefrontal cortex and attenuated prediction error signals in the ventral striatum. These results suggest that the mere expectation of reward can drive learning.
- Liane Schmidt
- Erin Kendall Braun
- Daphna Shohamy