Scalar words such as 'warm' often give rise to inferences like 'warm but not hot'. Under standard accounts, such scalar implicatures are derived by negating stronger alternatives. Research has shown that in online processing, weaker scale-mates ('warm') prime stronger ones ('hot'), suggesting that the latter are used in implicature processing (De Carvalho et al, 2016; Ronai & Xiang, 2023). We test different theories of scalar implicature processing by examining whether priming holds when no implicature is expected to arise. This is crucial to know whether and what kinds of alternatives form the basis of scalar implicature computation. We first focused on sentences with negation and asked whether 'hot' is primed when comprehenders are exposed to sentences containing 'not warm'. Then, we tested antonyms, such as 'cool', which are assumed to be on a separate scale. Lastly, we tested negated antonyms (i.e., 'not cool'). As a control, we also ran an experiment with isolated antonym words without any sentential context. In line with theoretical accounts (Horn, 1972), negated scale-mates did not prime strong ones. Contrary to these accounts, however, antonyms primed the target words ('hot'). Negation seems to have also cancelled the activation of targets for antonymic primes. In a joint analysis of our sentential experiments with the addition of the data from Ronai & Xiang (2023), which tested the priming by non-negated scale-mates, we found that negation interacted with both scale-mate primes and antonym primes. We explain these findings within the Alternative Activation Account (Gotzner, 2017), which assumes an initial activation of a broad cohort of associated expressions and their subsequent grammatical and contextual narrowing.