Effect of response effort on secondary reward value

This study tested whether a distinctive secondary rewarding stimulus (a black or a white goal box) of a Y-maze associated with a difficult response (running "uphill") would be preferred to the box associated with an easy response (running on a horizontal plane). Ii so, it would indicate that secondary reward value was positively related to response difficulty in organisms having little in the way of cultural conditioning, namely, laboratory rats. The data, however, showed no such preference.