Affective states associated with morphine injections (Rossi 1976)
- They used a 98 x 23 x 29 cm alley that was divided into three distinct compartments each separated by the middle compartment (8 x 23 x 29 cm) having guillotine doors on each side.
- The middle compartment was gray, had a solid floor, and served as a starting point for the animals during the testing procedure.
- On one side of the middle compartment was a black compartment with 1.3 x 2.5 cm with wire mesh floor, which they referred to as the black side.
- On the other side of the middle compartment was a white compartment with a 1.3 x 1.3 cm wire mesh floor, which they referred to as the white side.