Oral perception of bolus in healthy young women

This study was designed to characterize oral perception of both weight and volume of boluses. A total of 80 healthy young female subjects was recruited and divided into bolus weight (n = 40) and bolus volume (n = 40) conditions. Tap water (25 degrees C) was the experimental material, and seven reference stimulus amounts ranging from 10 to 40 (grams and mL) were prepared. The reference stimuli, including a modulus of 20 (grams and mL), were delivered to the: subjects in randomized order. The estimated magnitudes (Psi) conformed to both the Fechner's and Stevens' psychophysical laws by the following equations: (1) Psi(W)=314.3 log (S+1) - 300.2 where S is stimulus intensity or weight, and Psi(V)=249.7 log (S+1) - 222.3 (volume) on logarithmic (log)-linear scales, and (2) Psi(W)= 1.908 Sr-1.297 and Psi(V) =4.097 S-1.032 on log-log scales, respectively. The results indicate that oral perception of bolus weight and bolus volume conforms to the representative psychophysical laws.