An important aspect of cognitive functioning of the human brain is the way the different mental contents are produced, stored and retrieved. This issue is also central to the study of language processing in relation to how to represent and process the meanings of the words. In several previous ERP studies we have looked at the role of different semantic dimensions of words when we are recognizing and processing them. For instance, we have shown that some processing differences between nouns and verbs can be reduced to the semantic features associated to those types of words, as the amount of motor or sensory features (Barber, Kousta, Otten, & Vigliocco, 2010; for a general review including neuropsychological and neuroimaging data see also Vigliocco, Vinson, Druks, Barber, & Cappa, 2011). In a related ERP study we compared the processing of concrete and abstract words keeping constant other semantic variables like their imageability or context availability. After these controls we could replicate the previous ERP concreteness effect but obtaining a behavioural advantage for abstract words, in contrast to previous reports (Barber, Otten, Kousta & Vigliocco; submitted). Such abstractness effect could be partially explained by the emotional valence of the words, because many abstract words have associated emotional information. All together these studies highlight that semantic variables are tightly interconnected in meaning representation and word processing.
The late second language learners is an interesting group to study, because it is getting more and more common to learn a language at school even later as an adult, and also because the study of second language learners can provide information on how the process of language acquisition in general develops. For example, whether characteristics of the first language (L1) transfer to the second language (L2), or how and on what level the two languages function independently on the long term. To put it briefly: whether or not the process of L2 acquisition follows a similar pattern as L1 learning. In a series of experiments we have looked at the electrophysiological correlates of grammatical gender and number processing in highly proficient late L2 learners of Spanish from different L1 backgrounds (English and Chinese), to explore the roles of age of acquisition, L2 proficiency and language transfer effects in L2 morphosyntax processing. The results from these studies indicate transfer effects, or in other words, that L1 grammar is used to support L2 learning, at least in late L2 learners (Gillon-Dowens, Vergara, Barber & Carreiras, 2010; Gillon-Dowens, Guo, Guo, Carreiras & Barber, 2011). Bilingualism also results in people that eventually have to manage switches between languages. In other related experiments, we analyzed this language switching phenomena when the languages are not balanced in proficiency; one is more dominant than the other. The results of these experiment show that language switching involves highly skilled cognitive control and its costs are clearly asymmetrical depending of the direction of the switching (Van der Meij, Cuetos, Carreiras & Barber, 2011; Van der Meij, Hernández, Carreiras & Barber, submited).