QUANTIFYING MOTIVATION USING A COMPUTER-CONTROLLED PUSH-DOOR

A computer-controlled push-door system was designed and tested as a method for measuring motivation. Eleven domestic hens were trained to use the push-door to gain access to food. They were deprived of food for 12 h or 43 h on 12 occasions and the push-door was used to measure the amount of "work" (measured as force × time) that they performed to gain access to a food reward. When deprived of food for 12 h the hens took significantly longer (P<0.01) to reach the required threshold of work, than when deprived for 43 h. This difference arose from the amount of time that the hens spent not pushing at the door. The problems encountered with this system and such an approach to measuring motivation are discussed. © 1990.