Özlem Ece Demir

When speech is ambiguous gesture steps in: Sensitivity to discourse-pragmatic principles in early childhood.

Young children produce gestures to disambiguate arguments. This study explores whether the gestures they produce are constrained by discourse-pragmatic principles: person and information status. We ask whether children use gesture more often to indicate the referents that have to be specified, i.e., 3(rd) person and new referents, than the referents that do not have to be specified, i.e., 1(st)/2(nd) person and given referents. Chinese- and English-speaking children were videotaped while interacting spontaneously with adults, and their speech and gestures were coded for referential expressions. We found that both groups of children tended to use nouns when indicating 3(rd) person and new referents but pronouns or null arguments when indicating 1(st)/2(nd) person and given referents. They also produced gestures more often when indicating 3(rd) person and new referents, particularly when those referents were ambiguously conveyed by less explicit referring expressions (pronouns, null arguments). Thus Chinese- and English-speaking children show sensitivity to discourse-pragmatic principles not only in speech but also in gesture.

Narrative skill in children with early unilateral brain injury: a possible limit to functional plasticity

Children with pre- or perinatal brain injury (PL) exhibit marked plasticity for language learning. Previous work has focused mostly on the emergence of earlier-developing skills, such as vocabulary and syntax. Here we ask whether this plasticity for earlier-developing aspects of language extends to more complex, later-developing language functions by examining the narrative production of children with PL. Using an elicitation technique that involves asking children to create stories de novo in response to a story stem, we collected narratives from 11 children with PL and 20 typically developing (TD) children. Narratives were analysed for length, diversity of the vocabulary used, use of complex syntax, complexity of the macro-level narrative structure and use of narrative evaluation. Childrens language performance on vocabulary and syntax tasks outside the narrative context was also measured. Findings show that children with PL produced shorter stories, used less diverse vocabulary, produced structurally less complex stories at the macro-level, and made fewer inferences regarding the cognitive states of the story characters. These differences in the narrative task emerged even though children with PL did not differ from TD children on vocabulary and syntax tasks outside the narrative context. Thus, findings suggest that there may be limitations to the plasticity for language functions displayed by children with PL, and that these limitations may be most apparent in complex, decontextualized language tasks such as narrative production.

Effects of age and language on co-speech gesture production: an investigation of French, American, and Italian children's narratives.

The aim of this paper is to compare speech and co-speech gestures observed during a narrative retelling task in five- and ten-year-old children from three different linguistic groups, French, American, and Italian, in order to better understand the role of age and language in the development of multimodal monologue discourse abilities. We asked 98 five- and ten-year-old children to narrate a short, wordless cartoon. Results showed a common developmental trend as well as linguistic and gesture differences between the three language groups. In all three languages, older children were found to give more detailed narratives, to insert more comments, and to gesture more and use different gestures--specifically gestures that contribute to the narrative structure--than their younger counterparts. Taken together, these findings allow a tentative model of multimodal narrative development in which major changes in later language acquisition occur despite language and culture differences.

Vocabulary, Syntax, and Narrative Development in Typically Developing Children and Children with Early Unilateral Brain Injury: Early Parental Talk about the "There-and-Then" Matters.

This study examines the role of a particular kind of linguistic input--talk about the past and future, pretend, and explanations, that is, talk that is decontextualized--in the development of vocabulary, syntax, and narrative skill in typically developing (TD) children and children with pre- or perinatal brain injury (BI). Decontextualized talk has been shown to be particularly effective in predicting childrens language skills, but it is not clear why. We first explored the nature of parent decontextualized talk and found it to be linguistically richer than contextualized talk in parents of both TD and BI children. We then found, again for both groups, that parent decontextualized talk at child age 30 months was a significant predictor of child vocabulary, syntax, and narrative performance at kindergarten, above and beyond the childs own early language skills, parent contextualized talk and demographic factors. Decontextualized talk played a larger role in predicting kindergarten syntax and narrative outcomes for children with lower syntax and narrative skill at age 30 months, and also a larger role in predicting kindergarten narrative outcomes for children with BI than for TD children. The difference between the 2 groups stemmed primarily from the fact that children with BI had lower narrative (but not vocabulary or syntax) scores than TD children. When the 2 groups were matched in terms of narrative skill at kindergarten, the impact that decontextualized talk had on narrative skill did not differ for children with BI and for TD children. Decontextualized talk is thus a strong predictor of later language skill for all children, but may be particularly potent for children at the lower-end of the distribution for language skill. The findings also suggest that variability in the language development of children with BI is influenced not only by the biological characteristics of their lesions, but also by the language input they receive.

Turkish- and English-speaking children display sensitivity to perceptual context in the referring expressions they produce in speech and gesture

Speakers choose a particular expression based on many factors, including availability of the referent in the perceptual context. We examined whether, when expressing referents, monolingual English- and Turkish-speaking children: (1) are sensitive to perceptual context, (2) express this sensitivity in language-specific ways, and (3) use co-speech gestures to specify referents that are underspecified. We also explored the mechanisms underlying childrens sensitivity to perceptual context. Children described short vignettes to an experimenter under two conditions: The characters in the vignettes were present in the perceptual context (perceptual context); the characters were absent (no perceptual context). Children routinely used nouns in the no perceptual context condition, but shifted to pronouns (English-speaking children) or omitted arguments (Turkish-speaking children) in the perceptual context condition. Turkish-speaking children used underspecified referents more frequently than English-speaking children in the perceptual context condition; however, they compensated for the difference by using gesture to specify the forms. Gesture thus gives children learning structurally different languages a way to achieve comparable levels of specification while at the same time adhering to the referential expressions dictated by their language.

Narrative Processing in Typically Developing Children and Children With Early Unilateral Brain Injury: Seeing Gesture Matters

Narrative skill in kindergarteners has been shown to be a reliable predictor of later reading comprehension and school achievement. However, we know little about how to scaffold childrens narrative skill. Here we examine whether the quality of kindergarten childrens narrative retellings depends on the kind of narrative elicitation they are given. We asked this question with respect to typically developing (TD) kindergarten children and children with pre- or perinatal unilateral brain injury (PL), a group that has been shown to have difficulty with narrative production. We compared childrens skill in retelling stories originally presented to them in 4 different elicitation formats: (a) wordless cartoons, (b) stories told by a narrator through the auditory modality, (c) stories told by a narrator through the audiovisual modality without co-speech gestures, and (e) stories told by a narrator in the audiovisual modality with co-speech gestures. We found that children told better structured narratives in response to the audiovisual + gesture elicitation format than in response to the other 3 elicitation formats, consistent with findings that co-speech gestures can scaffold other aspects of language and memory. The audiovisual + gesture elicitation format was particularly beneficial for children who had the most difficulty telling a well-structured narrative, a group that included children with larger lesions associated with cerebrovascular infarcts.

The Differential Role of Verbal and Spatial Working Memory in the Neural Basis of Arithmetic

We examine the relations of verbal and spatial working memory (WM) ability to the neural bases of arithmetic in school-age children. We independently localize brain regions subserving verbal versus spatial representations. For multiplication, higher verbal WM ability is associated with greater recruitment of the left temporal cortex, identified by the verbal localizer. For multiplication and subtraction, higher spatial WM ability is associated with greater recruitment of right parietal cortex, identified by the spatial localizer. Depending on their WM ability, children engage different neural systems that manipulate different representations to solve arithmetic problems.

Parental socioeconomic status and the neural basis of arithmetic: differential relations to verbal and visuo-spatial representations

We examined the relation of parental socioeconomic status (SES) to the neural bases of subtraction in school-age children (9- to 12-year-olds). We independently localized brain regions subserving verbal versus visuo-spatial representations to determine whether the parental SES-related differences in childrens reliance on these neural representations vary as a function of math skill. At higher SES levels, higher skill was associated with greater recruitment of the left temporal cortex, identified by the verbal localizer. At lower SES levels, higher skill was associated with greater recruitment of right parietal cortex, identified by the visuo-spatial localizer. This suggests that depending on parental SES, children engage different neural systems to solve subtraction problems. Furthermore, SES was related to the activation in the left temporal and frontal cortex during the independent verbal localizer task, but it was not related to activation during the independent visuo-spatial localizer task. Differences in activation during the verbal localizer task in turn were related to differences in activation during the subtraction task in right parietal cortex. The relation was stronger at lower SES levels. This result suggests that SES-related differences in the visuo-spatial regions during subtraction might be based in SES-related verbal differences.

A tale of two hands: children's early gesture use in narrative production predicts later narrative structure in speech.

Speakers of all ages spontaneously gesture as they talk. These gestures predict childrens milestones in vocabulary and sentence structure. We ask whether gesture serves a similar role in the development of narrative skill. Children were asked to retell a story conveyed in a wordless cartoon at age five and then again at six, seven, and eight. Childrens narrative structure in speech improved across these ages. At age five, many of the children expressed a characters viewpoint in gesture, and these children were more likely to tell better-structured stories at the later ages than children who did not produce character-viewpoint gestures at age five. In contrast, framing narratives from a characters perspective in speech at age five did not predict later narrative structure in speech. Gesture thus continues to act as a harbinger of change even as it assumes new roles in relation to discourse.

Perinatal focal brain injury: scope and limits of plasticity for language functions

Children with perinatal focal brain injury exhibit normal or near-normal language development even when lesions are large and encompass classic left hemisphere perisylvian language networks. Their language difficulties are much more subtle than those seen in adults with similar lesions. We review the literature on the effects of perinatal injury on language development, with a focus on the scope and limits of functional plasticity, the relation between biological characteristics of lesions and language input on functional plasticity, and potential mechanisms of language plasticity after early lesions. The literature on the plasticity for language functions after perinatal focal brain injury presents a challenge to theories that posit an immutable brain basis for language and is consistent with the view of a dynamic, plastic brain—a developing brain capable of responding to internal biological signals, including those associated with injury, and to information provided by the environment.Children with perinatal focal brain injury exhibit normal or near-normal language development even when lesions are large and encompass classic left hemisphere perisylvian language networks. Their language difficulties are much more subtle than those seen in adults with similar lesions. We review the literature on the effects of perinatal injury on language development, with a focus on the scope and limits of functional plasticity, the relation between biological characteristics of lesions and language input on functional plasticity, and potential mechanisms of language plasticity after early lesions. The literature on the plasticity for language functions after perinatal focal brain injury presents a challenge to theories that posit an immutable brain basis for language and is consistent with the view of a dynamic, plastic brain—a developing brain capable of responding to internal biological signals, including those associated with injury, and to information provided by the environment.