Water, sucrose and three intensive sweet substances, dihydrochalcone, aspartame and saccharin, were flowed over the dorsal anterior tongue surface, both as preadapting rinses and as test stimuli following the rinses, in order to assess cross adaptation. All substances adapted themselves and were cross adapted by sucrose. However, either partial cross adaptation or no cross adaptation occurred when the intensive sweeteners were the preadapting rinse, suggesting multiple peripheral mechanisms encoding the sweet taste.