Disparate semantic ambiguity effects from semantic processing dynamics rather than qualitative task differences

Epub ahead of print 19/05/2016A core challenge in the semantic ambiguity literature is understanding why the number and relatedness among a word’s interpretations are associated with different effects in different tasks. An influential account (Hino et al., 2006) attributes these effects to qualitative differences in the response system. We propose instead that these effects reflect changes over time in settling dynamics within semantics. We evaluated the accounts using a single task, lexical decision, thus holding the overall configuration of the response system constant, and manipulated task difficulty – and the presumed amount of semantic processing – by varying nonword wordlikeness and stimulus contrast. We observed that as latencies increased, the effects generally (but not universally) shifted from those observed in standard lexical decision to those typically observed in different tasks with longer latencies. These results highlight the importance of settling dynamics in explaining many ambiguity effects, and of integrating theories of semantic dynamics and response systems.This work was funded by an NSERC CGS [grant number 432454] and a Marie Curie IIF [grant number FP7- PEOPLE-2013-IIF] awarded to BCA, & by Severo Ochoa program grant SEV-2015-049