Poster E28, Saturday, August 18, 3:00 – 4:45 pm, Room 2000AB
Dissociating the Role of Repetition and Semantic Association
Neus Ramos Escobar1,2, Clement Francois1,2, Mtti Laine3, Antoni Rodriguez-Fronells1,2,4;1Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet de Llobregat, Barcelona, Spain, 2Department of Basic Psychology, Campus Bellvitge, University of Barcelona, L’Hospitalet de Llobregat, Barcelona 08097, Spain, 3Department of Psychology, Abo Akademi University, Turku, Finland, 4Catalan Institution for Research and Advanced Studies, ICREA, Barcelona, Spain
Vocabulary acquisition is an essential component of language learning. The word-to-world mapping process in adults requires that learners create new links between arbitrary sounds and symbols and conceptual representations. This is a complex process that involves the initial familiarization (repetition exposure) with the orthographic or phonologic features of the word, an association of the word with the corresponding object or meaning and the final integration of this word to the current lexicon. Here we conducted two new ERP experiments to track the time course and development of the word-to-world mapping process during learning, controlling for the effects of new-word repetition (exposure effects) and conceptual binding (associating the new-word to an existing concept). Specifically, we aimed to investigate on how these processes develop in time (from one day to repeated training along days) and to disentangle the role of simple repetition of new word forms from the process of binding new-words to an existing concept during vocabulary acquisition. With these aims, in Experiment 1, we examined the brain responses of 25 adult participants acquiring a new vocabulary (novel objects with non-word pairs) over five consecutive sessions and a follow-up evaluation 4 months later. Three memory tasks (overt naming, covert naming and recognition tasks) were administered during each session and in the follow-up. EEG was recorded during the first and last training sessions. In Experiment 2 we replicated session 1 of Experiment 1 but, differentially, participants were assigned into two different groups (N=19 in each group). For the Learning Group (LG) the associations object-word were consistent, but for the No Learning Group (NL), the associations object-word were inconsistent (no semantic learning was possible). The ERP results for Experiment 1 revealed a near linear increase on the amplitude of the LPC with repeated exposure to pictures in centro-posterior brain regions. In contrast, a linear decrease on the N400 amplitude at fronto-central sites was observed across training when new-words were associated with a particular meaning (picture). In Experiment 2, both behavioral and ERP data showed evidence of learning with correctly learned associations eliciting a linear decrease of N400 amplitude through training in the LG but not in the NLG. A decrease in the amplitude of the P200 component for new-words in parietal electrodes was also found in the NLG but interestingly, not in the LG. These results provide new evidences regarding the role of semantic integration and repetition effects (familiarization to new-forms) during language learning and how these processes modulated the N400/P2. We also showed evidences that the learning process is boosted when new-words are associated with a particular meaning most probably through faster integration of the new traces into the existing semantic networks.
Topic Area: Meaning: Lexical Semantics