Margaret Friend

Developmental changes in sensitivity to vocal paralanguage

Developmental changes in childrens sensitivity to the role of acoustic variation in the speech stream in conveying speaker affect (vocal paralanguage) were examined. Four-, 7- and 10-year-olds heard utterances in three formats: low-pass filtered, reiterant, and normal speech. The availability of lexical and paralinguistic information varied across these three formats in a way that required children to base their judgments of speaker affect on different configurations of cues in each format. Across ages, the best performance was obtained when a rich array of acoustic cues was present and when there was no competing lexical information. Four-year-olds performed at chance when judgments had to be based solely on speech prosody in the filtered format and they were unable to selectively attend to paralanguage when discrepant lexical cues were present in normal speech. Seven-year-olds were significantly more sensitive to the paralinguistic role of speech prosody in filtered speech than were 4-year-olds and there was a trend toward greater attention to paralanguage when lexical and paralinguistic cues were inconsistent in normal speech. An integration of the ability to utilize prosodic cues to speaker affect with attention to paralanguage in cases of lexical/paralinguistic discrepancy was observed for 10-year-olds. The results are discussed in terms of the development of a perceptual bias emerging out of selective attention to language.

The transition from affective to linguistic meaning

This paper reports a transition from affective to linguistic meaning in 15-month-old infants. Behaviour regulation in the context of a social referencing procedure is used as a measure of the meaning of stimulus messages for infants. Of particular interest is the extent to which receptive vocabulary predicts behaviour regulation by language and paralanguage. Approving and disapproving lexical content was completely crossed with approving and disapproving facial and vocal paralanguage to produce stimulus messages. At the group level, the behaviour of 15-month-olds was better regulated by paralanguage than by lexical content. However, receptive vocabulary was a significant predictor of the relative primacy of language and paralanguage: infants who understood the lexical content of stimulus messages were better regulated by lexical content than by paralanguage. These data suggest a transition from affective to linguistic meaning in comprehension that parallels the transition from affective expression to expression that integrates affect and language.

Reliability and validity of the computerized comprehension task (CCT): data from American English and Mexican Spanish infants.

Early language comprehension may be one of the most important predictors of developmental risk. The need for performance-based assessment is predicated on limitations identified in the exclusive use of parent report and on the need for a performance measure with which to assess the convergent validity of parent report of comprehension. Child performance data require the development of procedures to facilitate infant attention and compliance. Forty infants (20 at 1;4 and 20 at 1;8) acquiring English completed a standard picture book task and the same task was administered on a touch-sensitive screen. The computerized task significantly improved task attention, compliance and performance. Reliability was high, indicating that infants were not responding randomly. Convergent validity with parent report and 4-month stability was substantial. Preliminary data extending this approach to Mexican-Spanish are presented. Results are discussed in terms of the promise of this technique for clinical and research settings and the potential influences of cultural factors on performance.

What Should I Do? Behavior Regulation by Language and Paralanguage in Early Childhood

This article explores the functional significance of affective messages for behavior in early childhood. Previous research indicates that childrens affective judgments are influenced more by what is said than by how it is said. Of particular interest is the extent to which this tendency toward literal interpretation has real consequences for behavior. The effect of consistent and conflicting affective messages on child behavior was assessed in a social-referencing procedure. What was said had a stronger effect than facial and vocal paralanguage on childrens exploration of novel objects. This suggests that the lexical bias evident in childrens interpretations reflects a genuine developmental transition in the primary cues on which attributions are based, and these cues have direct consequences for behavior regulation.

An infant-based assessment of early lexicon acquisition

The majority of research on the acquisition of spoken language has focused on language production, due to difficulties in the assessment of comprehension. A primary limitation to comprehension assessment is maintaining the interest and attention of younger infants. We have developed an assessment procedure that addresses the need for an extensive performance-based measure of comprehension in the 2nd year of life. In the interest of developing an engaging approach that takes into account infants’ limited attention capabilities, we designed an assessment based on touchscreen technology. This approach builds upon prior research by combining standardization and complexity with an engaging infant-friendly interface. Data suggest that the touchscreen procedure is effective in eliciting and maintaining infant attention and will yield more extensive and reliable estimates of early comprehension than do other procedures. The software to implement the assessmentis available free of charge for academic purposes.

The effects of bilingual growth on toddlers’ executive function

The mastery of two languages provides bilingual speakers with cognitive benefits over monolinguals, particularly on cognitive flexibility and selective attention. However, extant research is limited to comparisons between monolinguals and bilinguals at a single point in time. This study investigated whether growth in bilingual proficiency, as shown by an increased number of translation equivalents (TEs) over a 7-month period, improves executive function. We hypothesized that bilingual toddlers with a larger increase of TEs would have more practice in switching across lexical systems, boosting executive function abilities. Expressive vocabulary and TEs were assessed at 24 and 31 months of age. A battery of tasks, including conflict, delay, and working memory tasks, was administered at 31 months. As expected, we observed a task-specific advantage in inhibitory control in bilinguals. More important, within the bilingual group, larger increases in the number of TEs predicted better performance on conflict tasks but not on delay tasks. This unique longitudinal design confirms the relation between executive function and early bilingualism.

A Longitudinal Assessment of the Home Literacy Environment and Early Language.

This longitudinal assessment concentrated on the relation between the Home Literacy Environment (HLE) and early language acquisition during infancy and toddlerhood. In Study 1, after controlling for SES, a broadly-defined HLE predicted language comprehension in 50 infants. In Study 2, 27 children and their primary caregivers returned for further analyses. Findings revealed that the HLE measured in infancy predicted language production in toddlerhood, and maternal redirecting behaviors measured in toddlerhood were negatively associated with expressive language. Results across both studies indicate the importance of a broadly-defined HLE (including joint attention and parent-child conversation) for language development. Taken together, these findings highlight the importance of the HLE in supporting both receptive and expressive vocabulary growth in the second and third years of life.

Evaluating the Predictive Validity of the Computerized Comprehension Task: Comprehension Predicts Production

Until recently, the challenges inherent in measuring comprehension have impeded our ability to predict the course of language acquisition. The present research reports on a longitudinal assessment of the convergent and predictive validity of the MacArthur-Bates Communicative Development Inventories: Words and Gestures (CDI: WG; Fenson et al., 1994, 1993, 2007) and the Computerized Comprehension Task (CCT; Friend & Keplinger, 2003, 2008). The CDI: WG and the CCT evinced good convergent validity; however, the CCT better predicted subsequent parent reports of language production. Language sample data in the 3rd year confirm this finding: The CCT accounted for 24% of the variance in unique word use. These studies provide evidence for the utility of a behavior-based approach to predicting the course of language acquisition into production.

Vocabulary size, translation equivalents, and efficiency in word recognition in very young bilinguals.

The present study examined early vocabulary development in fifty-nine French monolingual and fifty French-English bilingual infants (1;4-1;6). Vocabulary comprehension was assessed using both parental report (MacArthur-Bates Communicative Development Inventory; CDI) and the Computerized Comprehension Task (CCT). When assessing receptive vocabulary development using parental report, the bilinguals knew more words in their L1 versus their L2. However, young bilinguals were as accurate in L1 as they were in L2 on the CCT, and exhibited no difference in speed of word comprehension across languages. The proportion of translation equivalents in comprehension varied widely within this sample of young bilinguals and was linked to both measures of vocabulary size but not to speed of word retrieval or exposure to L2. Interestingly, the monolinguals outperformed the bilinguals with respect to accuracy but not reaction time in their L1 and L2. These results highlight the importance of using multiple measures to assess early vocabulary development.

Minimal second language exposure, SES, and early word comprehension: New evidence from a direct assessment

Although the extant literature provides robust evidence of the influence of language exposure and socioeconomic status (SES) on language acquisition, it is unknown how sensitive the early receptive vocabulary system is to these factors. The current study investigates effects of minimal second language exposure and SES on the comprehension vocabulary of 16-month-old children in the language in which they receive the greatest exposure. Study 1 revealed minimal second language exposure and SES exert significant and independent effects on a direct measure of vocabulary comprehension in English-dominant and English monolingual children (N = 72). In Study 2, we replicated the effect of minimal second language exposure in Spanish-dominant and Spanish monolingual children (N = 86), however no effect of SES on vocabulary was obtained. Our results emphasize the sensitivity of the language system to minimal changes in the environment in early development.