The characteristics of olfactory memory during development were investigated and the hypothesis that the pleasantness of smells may be affected by previous associations with pleasant or unpleasant objects or events was tested. This type of emotional memory was compared in the immediate and long-term recognition of olfactory stimuli. Children from three different age groups (mean ages: 6 years 6 months; 8 years 9 months; and 10 years 5 months) were subdivided into two groups. One group was presented with six different odours, each with a slide depicting a pleasant picture. The other group was presented with the odours accompanied by unpleasant pictures. Immediately after stimulus presentation the subjects underwent a recognition test. One month later the subjects underwent a second recognition test, at the end of which they were required to give an evaluation of the pleasantness of each odour on a nine-point scale. At no age level did the pictures matched to the odours affect the recognition score. Olfactory memory varied with age, chiefly because memory decay increased with age, perhaps because of greater proactive interference. With increasing age more rapid decay was set against better immediate recognition. The hypothesis that the hedonic characteristics of odours are partially learned and are affected by events experienced in other modalities was supported.
Differential conditioning and long-term olfactory memory in individual Camponotus fellah ants
