Watching the Brain during Meaning Acquisition

Abstract

Acquiring the meaning of a new word in a foreign language can be achieved either by rote memorizing or, similar to meaning acquisition during infancy, by extracting it from context. Little is known about the brain mechanisms involved in word learning. Here we demonstrate, using event-related brain potentials, the rapid development of a brain signature related to lexical and semantic processing during contextual word learning. Healthy volunteers engaged in a simple word-learning task were required to discover the meaning of a novel word from a context during silent reading. After 3 exposures, brain potentials to novel words in meaningful contexts were indistinguishable from real words, although this acquisition effect was not observed for novel words, for which sentence contexts allowed no meaning derivation. Furthermore, when the learned novel words were presented in isolation, an activation of their corresponding meaning was observed, although this process was slower than for real words.

Professional Music Training and Novel Word Learning: From Faster Semantic Encoding to Longer-lasting Word Representations

“…This finding extends previous results on word learning showing N400 enhancements when learning a second language (McLaughlin et al, 2004), the meaning of rare words (Perfetti et al, 2005), and when learning the meaning of novel words or pseudowords from highly constrained sentence contexts (Borovsky et al, 2010(Borovsky et al, , 2012Batterink & Neville, 2011;Mestres-Missé et al, 2007). Importantly, and in line with previous work in adults (Borovsky et al, 2012;Mestres-Missé et al, 2007) and in children (François et al, 2013;Friedrich & Friederici, 2008), in both musicians and controls the N400 component to novel words was larger frontocentrally than parietally. These results are compatible with previous findings, suggesting that prefrontal and temporal brain regions are associated with the maintenance of novel information in working memory (Hagoort, 2014) and the acquisition of word meaning (Rodriguez-Fornells et al, 2009).…”

“…In musicians and for both tasks, the N400 over centroparietal sites was larger for unexpected (mismatch/unrelated) than for expected words (match/related; Figures 5 and 6). This sensitivity to word characteristics and this scalp distribution correspond to the N400 component, typically considered as the electrophysiological marker of the integration of novel words' meanings into semantic memory (Borovsky et al, 2012;Batterink & Neville, 2011;Mestres-Missé et al, 2007) and "as reflecting the activity in a multimodal long-term memory system that is induced by a given input stimulus during a delimited time window as meaning is dynamically constructed" (Kutas & Federmeier, 2011, p. 22; see also Steinbeis & Koelsch, 2008, for N400s elicited by single chords incongruous with the preceding context). By contrast, in nonmusician controls, the N400 effect was reversed over frontocentral sites in both tasks, with larger N400 for expected (match/related) than for unexpected words (mismatch/unrelated).…”

“…Specifically, results showed N400 enhancements in native English speakers after 14 hr of learning the meaning of novel French words (McLaughlin, Osterhout, & Kim, 2004) and after 45 min of learning the meaning of rare words (e.g., "clowder"; Perfetti, Wlotko, & Hart, 2005). Moreover, if a novel word (Borovsky, Elman, & Kutas, 2012;Borovsky, Kutas, & Elman, 2010;Mestres-Missé, Rodriguez-Fornells, & Münte, 2007) or pseudoword (Batterink & Neville, 2011) is presented in a strongly constrained and meaningful context, even a single exposure can be sufficient to build up initial word representations, an effect referred to as "fast mapping" (Carey, 1978). An incubation-like period and further exposures are then required for consolidation and integration into existing lexical networks (Dumay & Gaskell, 2007).…”

“…The general hypothesis was that the optimization of perceptual and cognitive functions in professional musicians would positively influence the speed and quality of word learning as reflected by a behavioral advantage for musicians (i.e., lower error rates [ERRs] and faster RTs). Moreover, based on the ERPs and word learning literature (Borovsky et al, 2010(Borovsky et al, , 2012Batterink & Neville, 2011;Mestres-Missé et al, 2007;Perfetti et al, 2005;McLaughlin et al, 2004), we expected a frontally distributed N400 component to develop in all participants during the early stages of novel word learning. However, if the perceptual and cognitive computations involved in word learning were facilitated in musicians, the development of the N400 component should be faster in musicians than in controls in the learning phase.…”

Functional Neuroanatomy of Meaning Acquisition from Context

“…In such studies, participants are exposed to different sources of information (linguistic and extralinguistic), which have to be used to determine the meaning of a novel word. In a previous study (Mestres-Missé, Rodriguez-Fornells, & Münte, 2007), we have adapted such a paradigm and recorded event-related brain potentials. A word-learning task (see Table 1) was created that allowed adult participants to derive the meaning of new words presented within three successive sentences.…”