The particular paper centers on antonymy and, in particular, it examines the salience of lexical semantic relations of adjectival antonyms in Swedish. The study attests the degree of goodness of opposability in certain adjectival pairs by means of two experiments. The first experiment is a semantic categorization task, where participants are asked to decide whether some adjectives are opposites or not. The antonyms are distinguished into three groups: canonical antonyms, non-canonical antonyms and unrelated words. The second experiment is the same as the first, with the exception that the adjectives are followed by a noun in order to provide participants with natural context. Both experiments performed neuroscan measurements. The findings of the first experiment showed that canonical antonyms have strong priming effects and that non- canonical antonyms could not be distinguished from unrelated words. In the second experiment, the presence of nouns led to significant differences between non-canonical antonyms and unrelated words pairs (adjectival pairs). Overall, the study shows that antonyms display different degree of strength of relatedness.