Olfactory Imagery

Phenomenal Imagery

People report that they can imagine odors. However, they also report that their images are not very vivid and are hard to generate, relative to their experience of visual and auditory images. Some more specific findings have also emerged. Olfactory experts report being better able to imagine odors than nonexperts and factor analysis of self-report measures of imagery in all modalities indicates that there is a separate olfactory/gustatory (taste) dimension. That these two modalities should appear together is no surprise, as they routinely combine to form flavor.

The difficulty in generating olfactory images and their lack of vividness may result from a number of causes. It has been suggested that smell perception may be less vivid and distinct than sensory experience in the other modalities, and so this may be reflected in imagined experiences too. However, certain smells can clearly capture attention (e.g., burning or leaking gas) and others may readily elicit strong emotions or distant memories. Consequently, this may not provide a convincing explanation for the reported lack of vividness and difficulty of evocation.

A further reason is that normal participants may simply be unpracticed at forming olfactory [Page 691]images, and the finding that experts are better in this regard suggests this possibility. Similarly, many imagery experiments begin in the following way: “Imagine the smell of lemon.” To form the image, some connection must exist between the word lemon and a memory of what lemon smells like. Interestingly, normal participants are very poor at naming odors (unlike olfactory experts) that are going from the odor percept to the name. It has been suggested that this is the flipside of going from a name to an odor memory, and that the impoverished nature of the odor-name link—which may result from lack of practice or poor neural connections—may explain why our capacity to imagine odors is not as good as imaging visual or auditory objects. Support for this notion comes from several sources. Hard to name odors are also hard to imagine (unlike their visual equivalents—try to visualize the smell of peanuts versus the sight of peanuts), but learning the odor's names improves self-report measures of imagery. More interestingly, nearly all of the successful performance imagery studies described in the next section involved participants learning the target odor names prior to imagining them.

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