Teaching adults new words: the role of practice and consolidation.

Semantic and orthographic learning of new words was investigated with the help of the picture-word interference (PWI) task. In this version of the Stroop task, picture naming is delayed by the simultaneous presentation of a semantically related as opposed to an unrelated distractor word (a specific PWI effect), as well as by an unrelated word compared with a nonword (a general PWI effect). This interference is taken to reflect automatic orthographic and semantic processing. The authors observed that participants showed both types of PWI effects for newly learned words following a single study session. Interestingly, specific PWI effects were not obtained immediately after testing but did emerge a week later without additional practice. This suggests that a period of consolidation is involved in the establishment of word representations. In addition, identical PWI effects were obtained when the study and test words were presented in either the same or different letter case. This provides evidence that the newly acquired orthographic representations are coded in an abstract format.