Patterns of generalization of perceptual learning on phonetic representations

Recent studies on perceptual learning have indicated that listeners use intermediate units between the acoustic input and lexical representations of words. The same paradigm may also reveal the nature of these intermediate units based on patterns of generalization of learning. We here test whether learning generalizes to other units of the same underlying or surface representation. This was achieved by exposing listeners to tensified Korean stops (i.e., underlying plain stops produced as tense due to a phonological process) and testing the consequences for later presented underlying tense or plain stops. Our results show that learning generalizes to underlying tense stops, while generalization to underlying plain stops could not be found. This indicates that the difference in the underlying phonological representation as tense or plain do not hinder learning as long as there is phonetic similarity on the surface.