Olfactory Dreams: Phenomenology, Relationship to Volitional Imagery and Odor Identification

Olfactory dreams—smelling in dreams—are uncommon but real, brief, and emotionally charged, resembling everyday odors. People who report such dreams are better at identifying real odors, an effect not explained by motivation or attention. The findings suggest that olfactory imagery exists but its occurrence depends on the strength of connections between olfactory and semantic memory, which are typically weak in olfaction.

Study at a glance

Abstract

Phenomenological evidence for olfactory sensation in the absence of appropriate stimulation—imagery—is inconclusive and draws most support from reports of olfactory hallucinations. The current study examined whether more convincing phenomenological evidence could be obtained from normal participants, by studying reports of their olfactory dreams. A questionnaire approach ( N = 284) revealed that olfactory dreams were uncommon, had features similar to actual olfaction (emotive and brief), were representative of odors encountered in everyday life, and were positively related to self-report volitional imagery ability. In addition, a sub-group ( N = 116) also completed an odor identification test. Participants who experienced olfactory dreams were significantly better at identifying odors, an effect not mediated by motivational or attentional factors. These findings suggest people can experience olfactory images although their occurrence may be governed by the strength of connections between olfactory and semantic memory—notoriously weak in olfaction.