Before revision:  We demonstate that in easy RATs (those solved by more than 64 \% subjects in 15 seconds) there are strong links directly connecting stimuli and response, and thus an efficient strategy consist in activating these direct links. In turn, the most efficient mechanism of solving medium and hard RATs consists of preferentially following what we call "moderately weak" associations.
After revision:  We demonstate that in easy RATs (those solved by more than 64