ABSTRACT.The differential sensitivity to sucrose or Aspartame in water was studied over the course of 90 min sessions, using a sequential method. The assessors had not eaten since 9 a.m. and the sessions began at 12 noon. Two factors were studied: water ingestion and solid sucrose ingestion every 5 min. The ingestion of water had no effect on discriminative sensitivity. However, the ingestion of solid sucrose had an effect; it maintained discriminant ability in contrast to the protocol without ingestion. The reason for this effect of sucrose is not known; it might be metabolic, hedonic or perhaps something else.