Intentional and incidental odour-colour binding in working memory

The question of how features are bound together in working memory has become a topic of much research in recent years. However, this is typically focused on visual and/or auditory stimuli. This study applies established feature binding procedures to investigate odour binding in working memory. Across three experiments, memory for intentionally and incidentally formed odour-colour pairings was tested. Experiment 1 showed that following explicit instruction to remember the odour-colour combinations, young adults can recall lists of 3-odour-colour pairings at levels above that of chance and exhibit a recency advantage for the last pairing in the list. In Experiment 2 participants were asked to prioritise the first pairing in the list or treat all list items equally. We observed only limited evidence of prioritisation affecting the serial position function. Experiment 3 explored whether odour-colour binding can be incidentally formed. Using a yes/no recognition procedure, accuracy did not differ for positive test probes that were presented in the same (bound) or different (unbound) colour to encoding (although some weak recency effects were shown with confidence ratings). Taken together, these findings suggest that odour-colour bindings can be formed in working memory, but functionality may be limited compared to that of visual feature binding.