Perhaps you should try some spelling variations:
pain decreased » pain decrease (Expand search), in decreased (Expand search), brain decreases (Expand search)
decrease pain » decreases pain (Expand search), decrease in (Expand search), decreased brain (Expand search)
decreased and » decreases and (Expand search), decrease and (Expand search), decreased in (Expand search)
and decrease » and decreases (Expand search), and decreased (Expand search), and increase (Expand search)
decrease art » decrease akt (Expand search), decreased akt (Expand search), decreased ant (Expand search)
decrease at » decrease akt (Expand search), decrease and (Expand search), decrease in (Expand search)
at decrease » rate decrease (Expand search), that decrease (Expand search), not decrease (Expand search)
art object » art objects (Expand search), smart object (Expand search), an object (Expand search)

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( decrease pain decreased AND decrease ) OR ( decrease at decrease art object ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease pain decreased and decrease ) OR ( decrease at decrease art object ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease pain decreased and decrease ) OR ( decrease at decrease art object ))*.