Support was not found for hyperresponsivity of cognitive control regions during reward selection or reward anticipation.
Finally, depression severity was predicted by activation in bilateral midfrontal gyrus during reward selection.
Instead, MDD participants showed hyperresponsivity in orbitofrontal cortex, a region associated with assessment of risk and reward, during reward selection, as well as decreased activation of the middle frontal gyrus and the rostral cingulate gyrus during reward selection and anticipation.
Functional magnetic resonance imaging (fMRI) data indicated that the MDD group was characterized by reduced activation of striatal reward regions during reward selection, reward anticipation, and reward feedback, supporting previous data indicating hyporesponsivity of reward systems in MDD.
Subsequently, they were confronted with a tone cue during reward-seeking that functions as a warning sign since lever pressing during tone presentation results in a probabilistic footshock.
During MRI scanning, participants performed a monetary incentive delay task, which is known to elicit robust activation of the ventral striatum during reward anticipation.
Our novel experimental design allowed us to assess the differential contributions of the hippocampus and other temporo-parietal areas to searching and reward processing during reward-based spatial learning.
The fMRI results demonstrate that HT, relative to placebo, increased the response of the striatum and ventromedial prefrontal cortex, two areas that have been shown to be respectively involved during reward anticipation and at the time of reward delivery.
Next, we directly compared activity during reward anticipation and consumption.
Why then did the NAc BOLD response of the two groups not differ during reward delivery?
We observed activation of the ventral striatum and enhanced memory formation during reward anticipation.
