CONICET | Buscador de Institutos y Recursos Humanos

In adults, language acquisition cannot be attained by mere exposure to the linguistic context, as is the case during infancy. Although the basis of this behavioral difference is unknown, it is possible that both groups rely on distinct learning mechanisms. For instance, implicit learning is highly relevant during language acquisition in infants (e.g. Gómez & Gerken 1999), while the acquisition of a second language (L2) in adults relies mainly on explicit mechanisms. Implicit learning is characterized as a passive process, where knowledge of information is acquired through simple exposure to it. Explicit learning, is characterized as a process where the structure of information is actively searched for. In the present work we studied whether adults could acquire new verbal meanings by a process of inferential learning, a process shown to be highly relevant in infants during language acquisition (Marklund & Lacerda 2006). 19 adults were trained by rapidly presenting 70 different examples of 5 geometric figures performing 6 possible movements. Each example was simultaneously described by an audiovisual sentence in an artificial language. During testing, new figure/movement combinations were presented in combination with sentences, half of which did not describe the movement shown in the image. Subjects had to respond rapidly whether the sentences corresponded to the image or not. 15 of 19 adults responded above chance (G-test). Analysis of eeg recordings during testing, showed a N-400 like component with maximal significant differences between correct and incorrect sentences in centro-parietal channels. Results show that adults can acquire new lexical meanings by a process of inferential learning, as has been shown in infants.