Feature overlap modulates rapid semantic but not lexical integration of novel associations by means of fast mapping

There is evidence that rapid integration of novel associations into cortical networks is possible if associations are acquired through a learning procedure called fast mapping (FM). FM requires precise visual discrimination of sometimes highly similar pictures of a previously unknown and a known item, and linking an unfamiliar label to the unknown item. In order to shed light on the mechanisms underlying learning through FM, we manipulated feature overlap between the two items as potential modulating factor. In Experiment 1, we found that labels of the unknown items generally evoked instantaneous lexical competition when encoded through FM, indicating rapid integration into lexical networks. In Experiment 2, we observed semantic priming immediately after FM encoding but only if the items shared many features. This indicates that whereas feature overlap leaves item-level lexical integration unaffected, it might mediate semantic integration of arbitrary picture-label associations, which could explain contradictory findings in the literature.\n\nHighlightsO_LIWe examined cortical integration of associations using implicit memory measures.\nC_LIO_LIFast mapping enables immediate integration of associations into cortical networks.\nC_LIO_LISemantic integration requires the discrimination between items sharing many features.\nC_LIO_LIItem-level lexical integration is unaffected by feature overlap.\nC_LI