Table 2.

Stimulus pairs used

Odor pairsMedium pairs
Jasmine versus vanillaFoam rubber versus plastic beads
Mulberry versus patchouliGravel versus BBs
Cinnamon versus gardeniaPine shavings versus shredded manila folders
  • The exemplars within a dimension were always used in pairs. That is, for example, whenever jasmine appeared as one odor within a discrimination, the other odor was vanilla. No two rats within the same group received the same combinations, but the lesion and control groups were matched. The order of presentation of exemplars and the combination of exemplars into positive (+) and negative (−) stimuli were determined by a pseudorandom series generated before testing.