Figure 2.

Preference to odor which was previously associated with three concentrations of sucrose solutions. The odor associated with 2% sucrose was significantly preferred compared with the odor associated with water. The odor associated with 30% sucrose was significantly avoided, and the preference for the odor associated with 20% was similar to that associated with water. The ordinate denotes the preference ratio obtained from the conventional two-bottle preference method as described in the text.