Perhaps you should try some spelling variations:
visual regions » visual response, visual neurons, visual responses
visual regime » fiscal regime, tidal regime, signal regime
space worlds » state worlds, places worlds, game worlds
2008 space » 2000 space, 2001 space, 2008 state
do primary » co primary, two primary, 2 primary
worlds do » worlds does, worlds die, worlds das

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: 2008 space worlds do primary ((visual regime) OR (visual regions)).
• Adding a wildcard symbol may retrieve word variants: 2008 space worlds do primary ((visual regime) or (visual regions))*.