Five days versus a lifetime: intense associative vocabulary training generates lexically integrated words.

PURPOSE The best predictor of successful language therapy in both the acute and chronic stages after stroke is the treatment intensity, i.e., number of hours trained per week. Associative learning should be particularly suited for intense training because it places low demands on (executive) cognitive functions. It is as of yet unresolved, however, whether associative training is a valid language learning approach. It could merely produce superficial associations of acoustic-visual information, which remain outside lexical and conceptual networks. METHODS We here examined if five days of associative training in a miniature vocabulary are sufficient for an integration of novel words into the learner's mental lexicon. Twelve healthy subjects were trained 20 min daily for five consecutive days simply by frequent couplings of object pictures with novel words. RESULTS Correct responses for couplings of novel words and object names increased from a chance level of 50 percent on day 1 to >90 percent accuracy on day 5. Prior to and immediately after the vocabulary training, a cross-modal semantic priming test was administered to determine the degree of lexical integration of the novel words into the language system already in situ. CONCLUSIONS Results show that learned novel words had acquired semantic characteristics, which were comparable to words of subjects' native language acquired over a lifetime. Thus, comprehensive integration of the novel words into existing conceptual and lexical networks occurred after just five days of training. This lays the foundation for probing associative training approaches in aphasia therapy, with the hope of increasing therapy efficiency.