Actually the control states are defined in preferences, down at the bottom. You can use the predefined ones like "Move Left(p1)" or define your own.
+ MouseKeyboard: Player 1 "Move Left" is down
-> Sprite: Set X to Sprite.X+1
Would move sprite to the right instead of to the left, or how ever you want it.
Note: you can also use control states as Boolean comparisons, as either 1 or 0.