From the article

"Knowledge about the world is stored in our semantic representations (that is, concepts that correspond to our knowledge about and experiences with the world). These semantic representations are structured following a similarity principle, such that the semantic representations of similar concepts are grouped closer together in neural and psychological space, and those of dissimilar concepts are farther apart1. Because stimuli often activate more than one concept, there is always some uncertainty when a person needs to identify which concept to retrieve. This mapping presents an ongoing challenge for those who are averse to uncertainty. One way to reduce this uncertainty is to separate the semantic representations that are activated by the same stimulus as much as possible in representational space. We posited that people structure their semantic representations in ways that satisfy their psychological needs, including the desire to reduce uncertainty. On the basis of classic work in cognitive science2, we hypothesized that to achieve this uncertainty-reduction goal, people who are averse to uncertainty should exhibit separated semantic representations, which would make each representation more easily identifiable."

Layman's language by the editorial team

"People who are averse to uncertainty usually have a strong motivation to mitigate uncertainty. In this work, the authors suggest that this motivation to decrease uncertainty might also affect semantic representations and related neural activity patterns. The reported findings are a fascinating demonstration of how individual differences can fundamentally affect our cognition"