ERP and behavioral effects of semantic ambiguity in a lexical decision task

In the present study we examined electrophysiological and behavioral correlates of ambiguous word processing. In a lexical decision task, participants were presented with ambiguous words with unrelated meanings (i.e., homonyms; e.g., bat), ambiguous words with related meanings (i.e., polysemes; e.g., newspaper), and unambiguous words (e.g., guitar). Ambiguous words elicited larger N400 amplitudes than unambiguous words and showed an advantage in RTs. Importantly, no differences were found between homonyms and polysemes, on either N400 amplitudes or in RTs. These results suggest that ambiguous words, regardless of the relatedness between their meanings, benefit from enhanced semantic activation in comparison to unambiguous words during word recognition.