Adults adapt to child speech in semantic use

Children acquire their first language while interacting with adults in a highly adaptive manner. While adaptation occurs at many linguistic levels such as syntax and speech complexity, semantic adaptation remains unclear due to the difficulty of efficient meaning extraction. In this study, we examine the adaptation of semantics with a computational approach based on distributional information. We show that adults, in their speech addressed to children, adapt their distributional semantics to that in the speech children produce. By analyzing semantic representations modeled from the Manchester corpus, a large longitudinal acquisition corpus of English, we find striking similarity of semantic development between child and child-directed speech, with a slight time lag in the latter. These findings provide strong evidence for the semantic adaptation in first language acquisition and suggest the important role of child-directed speech in semantic learning.

Learning Orthographic and Semantic Representations Simultaneously During Shared Reading

Purpose The value of shared reading as an opportunity for learning word meanings, or semantics, is well established; it is less clear whether children learn about the orthography, or word spellings, in this context. We tested whether children can learn the spellings and meanings of new words at the same time during a tightly controlled shared reading session. We also examined whether individual differences in either or both of orthographic and semantic learning during shared reading in English were related to word reading in English and French concurrently and 6 months longitudinally in emergent English–French bilinguals. Method Sixty-two Grade 1 children (35 girls; M age = 75.89 months) listened to 12 short stories, each containing four instances of a novel word, while the examiner pointed to the text. Choice measures of the spellings and meanings of the novel words were completed immediately after reading each set of three stories and again 1 week later. Standardized measures of word reading as well as controls for nonverbal reasoning, vocabulary, and phonological awareness were also administered. Results Children scored above chance on both immediate and delayed measures of orthographic and semantic learning. Orthographic learning was related to both English and French word reading at the same time point and 6 months later. In contrast, the relations between semantic learning and word reading were nonsignificant for both languages after including controls. Conclusion Shared reading is a valuable context for learning both word meanings and spellings, and the learning of orthographic representations in particular is related to word reading abilities. Supplemental Material https://doi.org/10.23641/asha.13877999

Serotonin modulates learning content-specific neuroplasticity of functional brain networks

Learning-induced neuroplastic changes, further modulated by content and setting, are mirrored in brain functional connectivity. Animal models emphasized the crucial role of serotonin in neuroplasticity particularly for emotional relearning, but comparable studies in humans are scarce. Assessing the translation of learning effects from animals to humans, 99 healthy subjects underwent six weeks of emotional or semantic learning and subsequent relearning and three resting-state acquisitions for functional connectivity estimation. During relearning, subjects received either a daily dose of the selective serotonin reuptake inhibitor escitalopram or placebo. The influence of escitalopram on functional connectivity was connection- and learning content-dependent, with potentiation of decreases during emotional and increases during semantic learning. The directedness of these effects indicates serotonergic modulation of emotional feedback routes. These results demonstrate that escitalopram intake during relearning facilitates content-dependent network adaptations and support the conclusion that enhanced neuroplasticity might be the major underlying mechanism in psychiatric therapies.