Odor-based context-dependent memory: influence of olfactory cues on declarative and nondeclarative memory indices.

Reinstating the olfactory learning context can increase access to memory information, but it is not fully clear which memory functions are subject to an enhancing odor context reinstatement effect. Here, we tested whether congruent odor context during encoding and recall positively affected declarative and nondeclarative memory scores using a novel method for manipulation of an odorous environment; namely, intranasal Nosa plugs. Recall of a text and a complex figure as well as performance in a priming task were assessed immediately and 1 wk after encoding. We found that congruent odor exposure at encoding and recall aided free retrieval of a story at delayed testing but had no significant effect on a complex figure recall or a word completion task. Differences between the assessed memory indices suggest that olfactory environmental cues may be primarily efficient in free verbal recall tasks.