EFFECTS OF VISUAL AND VERBAL INTERFERENCE TASKS ON OLFACTORY MEMORY -THE ROLE OF TASK COMPLEXITY

Recent studies have demonstrated that visual and verbal suppression ta sks interfere with olfactory memory in a manner which is partially con sistent with a dual coding interpretation. However, it has been sugges ted that total task complexity rather than modality specificity of the suppression tasks might account for the observed pattern of results. This study addressed the issue of whether or not the level of difficul ty and complexity of suppression tasks could explain the apparent moda lity effects noted in earlier experiments. A total of 608 participants were each allocated to one of 19 experimental conditions involving in terference tasks which varied suppression type (visual or verbal), nat ure of complexity (single, double or mixed) and level of difficulty (e asy, optimal or difficult) and presented with 13 target odours. Either recognition of the odours or free recall of the odour names was teste d on one occasion, either within 15 minutes of presentation or one wee k later. Both recognition and recall performance showed an overall eff ect for suppression nature, suppression level and time of testing with no effect for suppression type. The results lend only limited support to Paivio's (1986) dual coding theory, but have a number of character istics which suggest that an adequate account of olfactory memory may be broadly similar to current theories of face and object recognition. All of these phenomena might be dealt with by an appropriately modifi ed version of dual coding theory.