Nihil in intellectu nisi prius in sensu?: Knowledge and conceptualization of olfactory information without the sense of smell

Giraudet, Eléonore [UCL] Mattioni, Stefania [UCL] Lettieri, Giada [UCL] Huart, Caroline [UCL] Collignon, Olivier [UCL]

“There is nothing in the intellect that was not first in the sense”. This famous quote attributed to Aristotle, represents the foundation of the empiricist view on how knowledge arises in the human mind. If true, one may therefore wonder how sensory deprived people conceive the things they cannot experience with their senses. The study of people born without olfaction represents a particularly interesting case to tackle such a question for two main reasons: 1) smell is a sensory quality that does not easily “remap” onto other properties of the other senses (e.g. you cannot hear or touch smell) and 2) because it has been demonstrated that, compared to the other senses, olfactory information is poorly accessible through language. How do people born without smell conceive olfactory information? To address this question, we asked congenital anosmic participants (N=20) and matched controls (N=20) to categorise and sort words with various olfactory values across five different tasks (property generation; card sorting; odd-one out; drag and rate; knowledge of the words) and two different conditions (neutral and olfactory). Our results show that despite important similarities between congenital anosmic and control people, they nonetheless show interesting qualitative discrepancies on how they think about olfactory content of things. Our study suggests that language allows a deep representation of odors even without ever experiencing them. However, such representation differs from the one of control people in significant ways, showing how sensory experience partially shapes our mental representation of things.