Perhaps you should try some spelling variations:
decrease signal » increased signal (Expand search), decrease stigma (Expand search), decrease renal (Expand search)
fear processing » pear processing (Expand search), fur processing (Expand search), after processing (Expand search)
signal decrease » signaling decreases (Expand search), signalling decreases (Expand search)
decrease fear » decreased fear (Expand search), decrease fetal (Expand search), decreased heart (Expand search)
decrease the » decreases the (Expand search), decrease in (Expand search), decrease of (Expand search)
the decrease » to decrease (Expand search), and decrease (Expand search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease the decrease fear processing ) OR ( decrease NOT decrease signal decrease ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease the decrease fear processing ) OR ( decrease NOT decrease signal decrease ))*.