Taste discrimination after separate pre-exposure and test sessions.

The effect of previous exposure on discrimination of two flavored solutions sharing a common taste was investigated in a pilot experiment. These solutions were at the limit of discrimination and the pre-exposure and test phases took place on different days. The results showed that mere pre-exposure (i.e., in absence of feedback) facilitates subsequent discrimination of same or different pairs of solutions. This result is in some aspects opposite to those reported recently by Dwyer and colleagues. This discrepancy is discussed analyzing the procedural differences observed between these studies.