Word Learning in the Developing Brain : ERP Dynamics of Learning Word-Object Associations

This dissertation investigated electrophysiological measures of individual differences in toddlers’ ability to learn novel object labels and process familiar object words and their referents. The studies measured both visual and auditory event-related potentials (ERPs) in response to pictures of objects and words in a longitudinal sample of 20- to 24-month-olds, an age of dynamic vocabulary development. These ERP measures were related to the children’s productive vocabulary size as well as behavioral measures of word comprehension and object recognition.Study I aimed to test children’s ability to map familiar words to versions of their referents displaying reduced visual information (only overall shape or isolated parts), and whether this ability correlated with vocabulary size. Children with larger vocabularies showed a stronger N400 incongruity effect in response to words paired with correct vs. incorrect shape referents specifically, and the N400 effect in the shape condition also correlated with the children’s ability to overtly identify objects from their overall shape in a behavioral test. These results are discussed in relation to previous research demonstrating the emergence of a shape bias in children’s Word extension, as well as improvements in object shape recognition, during the second year of life.Study II investigated individual differences in novel word-object mapping andchanges with age in this ability. The overall sample showed ERP evidence of novel word learning (an N400 semantic incongruity effect) after five consistent word-object pairings at 24 months but not at 20 months. Children with large vocabularies demonstrated the same linear attenuation of N400 amplitude during novel word repetition as is commonly seen in adults, while children with smaller vocabularies did not show such attenuation until the end of the learning phase.Study III focused on the 20 month data set and explored how visual ERPs weremodulated as object-word pairs were presented repeatedly, and how these measures of visual object processing related to successful fast mapping of the novel words to the objects. A larger attenuation of the Nc component (associated with attention) predicted successful word learning, measured as a larger N400 incongruity effect to the novel words after training. Furthermore, better initial recognition of familiar objects correlated with a stronger N400 effect to the words for those objects. The results present novel evidence for a link between efficient visual processing of objects and word learning ability.Taken together, these findings demonstrate that the rapid vocabulary growth and striking individual differences in productive vocabulary development seen during children’s second year are linked to the dynamics of specific brain mechanisms involved in semantic processing of words and their referents

Implicit foreign language learning after minimal exposure across the lifespan

Langues étrangères

Attention Restraint, Working Memory Capacity, and Mind Wandering: Do Emotional Valence or Intentionality Matter?

Attention restraint appears to mediate the relationship between working memory capacity (WMC) and mind wandering (Kane et al., 2016). Prior work has identifed two dimensions of mind wandering—emotional valence and intentionality. However, less is known about how WMC and attention restraint correlate with these dimensions. Te current study examined the relationship between WMC, attention restraint, and mind wandering by emotional valence and intentionality. A confrmatory factor analysis demonstrated that WMC and attention restraint were strongly correlated, but only attention restraint was related to overall mind wandering, consistent with prior fndings. However, when examining the emotional valence of mind wandering, attention restraint and WMC were related to negatively and positively valenced, but not neutral, mind wandering. Attention restraint was also related to intentional but not unintentional mind wandering. Tese results suggest that WMC and attention restraint predict some, but not all, types of mind wandering

The role of phonology in visual word recognition: evidence from Chinese

Posters - Letter/Word Processing V: abstract no. 5024The hypothesis of bidirectional coupling of orthography and phonology predicts that phonology plays a role in visual word recognition, as observed in the effects of feedforward and feedback spelling to sound consistency on lexical decision. However, because orthography and phonology are closely related in alphabetic languages (homophones in alphabetic languages are usually orthographically similar), it is difficult to exclude an influence of orthography on phonological effects in visual word recognition. Chinese languages contain many written homophones that are orthographically dissimilar, allowing a test of the claim that phonological effects can be independent of orthographic similarity. We report a study of visual word recognition in Chinese based on a mega-analysis of lexical decision performance with 500 characters. The results from multiple regression analyses, after controlling for orthographic frequency, stroke number, and radical frequency, showed main effects of feedforward and feedback consistency, as well as interactions between these variables and phonological frequency and number of homophones. Implications of these results for resonance models of visual word recognition are discussed.postprin

Stratégies d'apprentissage et mémoire à long terme d'associations mot-objet chez le jeune enfant et le chien

Nous faisons tous l'expérience de nous souvenirs d'informations ou d'épisodes de vie vécus il y a fort longtemps. Mais qu'en est-il pour nos jeunes enfants et pour les espèces animales éloignées de nous ? Les enfants et les animaux forment-ils également des souvenirs qui peuvent demeurer intacts durant de longues périodes ? Et si tel est le cas, la formation de leurs souvenirs dépend-elle des mêmes règles que celles actuellement établies chez l'Homme adulte ? Cette thèse s'est intéressée à ces questions dans un contexte d'apprentissage associatif bimodal complexe: le concept mot-objet; chez le jeune enfant et le chien domestique. Pour ces deux modèles d'étude, nous avons exploré certains paramètres susceptibles de faciliter l'encodage et le stockage en mémoire de ce type d'information. Nous avons notamment cherché à savoir si le nombre de présentations de nouvelles associations mot-objets lors de l'apprentissage avait un effet sur la rétention du nom de ces objets après un délai, et avons tenté de déterminer le nombre minimal de présentations nécessaire pour induire une trace mnésique. Enfin, nous avons exploré l'efficacité de deux stratégies d'apprentissage sur la mémorisation de nouveaux noms d'objets et démontrons que l'efficacité des stratégies utilisées chez l'Homme évolue au cours du développement de l'enfant et ne semblent pas s'appliquer aux chiens. En bref, nos résultats apportent des éclaircissements quant à certains principes qui sous-tendent la formation de mémoires sensorielles chez un organisme en développement ainsi que chez une espèce animale non primate, et nous permettent d'émettre des hypothèses quant aux mécanismes cérébraux sous-jacents.All of us occasionally remember information or personal events that occurred a long time ago. But what about young children and distantly related animal species? Do young children and animals also form memories that can last in time? And if so, does memory formation rely on the same principles than those established in human adults? This thesis intended to examine these questions in the context of an associative learning concept involving complex bimodal stimuli: the word-object concept; both in young children and domestic dogs. For these two models, we explored some parameters susceptible to facilitate the encoding and storage of this type of information in memory. In particular, we attempted to determine if the number of presentations of novel word-object associations during learning influenced the retention of the name of these objects after a delay. We also aimed to establish the minimal number of presentations of the pairs required to induce a memory trace. Finally, we examined the efficacy of two learning strategies on the ability to remember the names of novel objects and demonstrated that the efficacy of the strategies implemented in humans evolves during development and seems not to apply to dogs. In brief, our results enlightened some principles underlying the formation of sensory memories in an early-developing brain system as well as in a non-primate species, and allow us to make assumptions about the underlying brain mechanisms

Interactive effects of orthography and semantics in Chinese picture naming

Posters - Language Production/Writing: abstract no. 4035Picture-naming performance in English and Dutch is enhanced by presentation of a word that is similar in form to the picture name. However, it is unclear whether facilitation has an orthographic or a phonological locus. We investigated the loci of the facilitation effect in Cantonese Chinese speakers by manipulating—at three SOAs (2100, 0, and 1100 msec)—semantic, orthographic, and phonological similarity. We identified an effect of orthographic facilitation that was independent of and larger than phonological facilitation across all SOAs. Semantic interference was also found at SOAs of 2100 and 0 msec. Critically, an interaction of semantics and orthography was observed at an SOA of 1100 msec. This interaction suggests that independent effects of orthographic facilitation on picture naming are located either at the level of semantic processing or at the lemma level and are not due to the activation of picture name segments at the level of phonological retrieval.postprin

Psychological Engagement in Choice and Judgment Under Risk and Uncertainty

Theories of choice and judgment assume that agents behave rationally, choose the higher expected value option, and evaluate the choice consistently (Expected Utility Theory, Von Neumann, & Morgenstern, 1947). However, researchers in decision-making showed that human behaviour is different in choice and judgement tasks (Slovic & Lichtenstein, 1968; 1971; 1973). In this research, we propose that psychological engagement and control deprivation predict behavioural inconsistencies and utilitarian performance with judgment and choice. Moreover, we explore the influences of engagement and control deprivation on agent’s behaviours, while manipulating content of utility (Kusev et al., 2011, Hertwig & Gigerenzer 1999, Tversky & Khaneman, 1996) and decision reward (Kusev et al, 2013, Shafir et al., 2002)

Neural mechanisms of visual categorization

The ability to categorize is a fundamental cognitive skill for animals, including human beings. Our lives would be utterly confusing without categories. We would feel overwhelmed or miss out on important aspects of our environment if we would perceive every single entity as one-of-a-kind. Therefore, categorization is of great importance for perception, learning, remembering, decision making, performing an action, certain aspects of social interaction, and reasoning. The seemingly effortless and instantaneous ability to transform sensory information into meaningful categories determines the success for interacting with our environment. However, the apparent ease with which we use categorization and categories conceals the complexity of the underlying brain processing that makes categorization and categorical representations possible. Therefore, the question arises: how are categorical information encoded and represented in the brain