STIMULUS EQUIVALENCE CLASSES INVOLVING OLFACTORY STIMULI

Adults were trained on a matching-to-sample task which initially invol ved matching either familiar, distinctive odor stimuli (smells) or les s familiar, less distinctive stimuli (perfumes) with nonsense syllable s (A --> B training). If they met a criterion of successful performanc e, they were transferred to a task where they had to match nonsense sy llables to line drawings (B-->C training). Following successful perfor mance, there was a test phase where the line drawings were presented a s samples with the odors as comparison stimuli (C-->A test phase). All participants who successfully completed A-->B training also successfu lly completed B-->C training, and 12 out of 14 selected the correct co mparison stimuli on 100% of C-->A test trials, with one further partic ipant achieving 97% success. This indicates that stimulus equivalence class formation had occurred, where one element of each stimulus class was an olfactory stimulus. Some participants failed to complete A-->B training successfully in the more difficult perfumes condition. This is consistent with literature from other learning paradigms. These fin dings have extended the generality of stimulus equivalence class forma tion and have implications for the role of verbal labeling. This exper iment also adds significantly to the growing body of recent literature which indicates similarities between olfactory memory and that involv ing other modalities.