Does an Impaired Sense of Smell Make it Harder to Think About Things like Garlic?

According to sensorimotor-based (also called "embodied" or "grounded") theories of semantic memory, accessing conceptual knowledge about things involves reactivating—or “simulating”—the sensory and motor experiences that we have had with them. For instance, thinking about things for which olfactory experience is dominant (e.g., garlic or a rose) would involve simulating their smell. However, evidence for olfactory simulation when thinking about "smelly” things is sparse and mixed. We tested smell-impaired (“anosmic”) and control participants (N=130 in the anosmic group and N=190 in the control group) on three tasks (1) Picture-Word Verification, (2) Semantic Property Verification, and (3) Free Recall. We predicted that anosmic participants should have more difficulty with smell/taste-experienced items compared to control participants but perform similarly on “non-smelly” items primarily experienced via other sensory or motor modalities (e.g., zipper, water). In preliminary analyses of picture-word verification and semantic property verification data, anosmic and control participants performed similarly across smelly and non-smelly items. Analyses were conducted by observing differences in accuracy and reaction time by subject and item. The patterns found suggest that olfactory simulation is not required for identifying or verifying properties of things experienced highly through smell, hinting that conceptual knowledge may not be entirely dependent on embodied sensory information.