Perhaps you should try some spelling variations:
reward processing » word processing (Expand search), onboard processing (Expand search), and processing (Expand search)
decrease reward » decrease awkward (Expand search), decrease towards (Expand search), increase rewards (Expand search)
decreases flow » decreases food (Expand search), decreases blood (Expand search), decreases brown (Expand search)
flow decrease » flow increase (Expand search), to decrease (Expand search), not decrease (Expand search)
decrease can » decrease in (Expand search), decrease and (Expand search), decrease at (Expand search)
can decrease » can increase (Expand search), and decrease (Expand search), to decrease (Expand search)

You may be able to get more results by adjusting your search query.

• Removing quotes may allow a broader search: (( decrease can decrease reward processing ) OR ( decreases flow decrease AND decrease ))~.