CONICET | Buscador de Institutos y Recursos Humanos

First language acquisition occurs by mere exposure to the linguistic context. Infants must infer word meanings by pairing specific aspects of their perceptual experience with particular segments of the concurrent linguistic input. This requires to statistically analyze cross-situational information. Under controlled experimental conditions, subjects can infer new noun and verbal meanings by conscious cross-situational pairing of images and auditory non-words, if they are given the explicit instruction to learn the presented terms. In the present work we studied if new verbal meanings could be learned implicitly, i.e. in the absence of intention to learn regularities between linguistic and contextual information. In order to do so, 22 right-handed healthy adults volunteered for the experiment. The first stage of the experiment consisted of 70 different visual scenes presented on a computer screen (two geometrical figures, one static and the other performing one of 6 possible movements). Simultaneously, a sentence describing the scene was presented auditorilly in an artificial language. Participants were told not to pay attention to the sentences and concentrate on classifying the movements they saw as ?horizontal? or ?non-horizontal? by pressing two different keys. They were had to learn which word denoted each movement. During the test stage 80 new scenes were shown, 40 of them presented a mismatch between the movement and the presented ?verb?. Subjects were told to decide on-line whether each sentence correctly described the scene. Simultaneous EEG recordings were obtained in this stage. Results showed that participants were completely unable to classify the sentences as correct or not. Nevertheless, the appearance of a mismatch between verb and referent elicited an ELAN-like potential. This difference could be reflecting differential learning strategies during the acquisition phase of the experiments.