Pui Fong Kan

Intervention for executive functions after traumatic brain injury: A systematic review, meta-analysis and clinical recommendations

A systematic review of studies that focused on the executive functions of problem solving, planning, organising and multitasking by adults with traumatic brain injury (TBI) was performed through 2004. Qualitative and quantitative methods were used to evaluate the 15 studies that met inclusion criteria. Demographic variables, design and intervention features, and impairment and activity/participation outcomes (ICF) (World Health Organization, 2001) were documented. Five randomised control treatment (RCT) studies used step-by-step, metacognitive strategy instruction (MSI) and outcomes were evaluated in a meta-analysis. Effect sizes (ESs) from immediate impairment outcomes after MSI and “control” intervention were similar to each other, and both were significantly larger than chance. ESs from immediate activity/participation outcomes after MSI were significantly larger than the ESs from control intervention, and both were significantly larger than chance. These results, along with positive outcomes from the other group, single-subject design and single case studies, provided sufficient evidence to make the clinical recommendation that MSI should be used with young to middle-aged adults with TBI, when improvement in everyday, functional problems is the goal (Level A) (American Academy of Neurology, 2004). Although maintenance effects were generally positive, there was insufficient data quantitatively to evaluate this. Furthermore, there was insufficient evidence to make clinical recommendations for children or older adults. Intervention that trained verbal reasoning and multi-tasking was promising, although the evidence is insufficient to make clinical recommendations at this time. Additional research needs were highlighted.

Performance on Nonlinguistic Visual Tasks by Children with Language Impairment.

The performance of 8- to 13-year-old monolingual English-speaking children with language impairment (LI) on seven nonlinguistic tasks was compared with two groups of typically developing children, monolingual English-speaking children, and proficient Spanish–English sequential bilingual children. Group differences were apparent, with a key finding that the LI group was observably slower than both typical groups in mental rotation and arithmetic, and also slower than the typical monolingual group in odd man out, pattern matching, and form completion. Overall, the response time (RT) increased equivalently across groups as task difficulty increased. Chronological age and perceptual–motor speed contributed to task performance, especially for the shorter tasks. RT trajectories across the 6-year age span showed that task RT decreased with age, but with greater variability for longer tasks that may also be more vulnerable to the effect of experience.

Lexical development in Mandarin–English bilingual children

Two groups of Mandarin–English bilingual children (3–5-year-olds, 6–8-year-olds) participated in a picture identification task and a picture naming task in both languages. Results revealed age-related growth in English, but not Mandarin vocabulary. Composite vocabulary was larger than either single-language vocabulary in the younger children but was similar to English vocabulary in the older children. Furthermore, children showed a larger receptive–expressive modality difference in their weaker language (Mandarin) than in their stronger language (English). These patterns indicate rapid growth in English vocabulary along with early stabilization of Mandarin vocabulary despite considerable Mandarin input in the home setting.

A Growth Curve Analysis of Novel Word Learning by Sequential Bilingual Preschool Children.

Longitudinal word learning studies which control for experience can advance understanding of language learning and potential intra- and inter-language relationships in developing bilinguals. We examined novel word learning in both the first (L1) and the second (L2) languages of bilingual children. The rate and shape of change as well as the role of existing vocabulary in new word learning were of primary interest. Participants were 32 three-to-five-year old children. All participants had Hmong as their L1 and English as their L2. A novel word learning paradigm was used to measure childrens acquisition of new form–meaning associations in L1 and L2 over eight weekly training sessions (four in each language). Two-level hierarchical linear models were used to analyze change in the comprehension and production of new words in Hmong and English over time. Results showed that there were comparable linear gains in novel word comprehension and production in both the L1 and the L2, despite different starting points. Success in novel word learning was predicted to some extent by existing vocabulary knowledge within each language. Between-language relationships were both positive and negative. These findings are consistent with highly interactive dynamic theories of sequential bilingual language learning.

Culturally Consistent Treatment for Late Talkers

The authors discuss cultural influences on clinical interactions when treating late talkers, 2- to 3-year-old children with primary language delays. They use the literature to examine the cultural relevance of core components of early language treatment and propose alternative professional actions in the cases of cultural mismatches. Alternative actions include triadic or multiparty treatments, the inclusion of siblings or others, more structured tasks or group settings for language training, and shaping of culturally congruent directive language techniques. Also discussed is the need for an emphasis on social language use and professional clarity regarding links between early child language ability and later achievements in order to motivate treatment.

Novel word retention in sequential bilingual children

Childrens ability to learn and retain new words is fundamental to their vocabulary development. This study examined word retention in children learning a home language (L1) from birth and a second language (L2) in preschool settings. Participants were presented with sixteen novel words in L1 and in L2 and were tested for retention after either a 2-month or a 4-month delay. Results showed that children retained more words in L1 than in L2 for both of the retention interval conditions. In addition, childrens word retention was associated with their existing language knowledge and their fast-mapping performance within and across language. The patterns of association, however, were different between L1 and L2. These findings suggest that childrens word retention might be related to the interactions of various components that are operating within a dynamic system.

Speech Practice Effects on Bilingual Children's Fast Mapping Performance.

Learning a new word involves many subsystems and their interactions. The purpose of this study was to examine whether speech practice facilitates the subsequent fast mapping performance of bilingual preschool children. Participants were 18 typically developing preschoolers who learned Cantonese (L1) as a home language and English (L2) as a second language. Each participant was asked to repeat each of the four novel words after an auditory model (speech practice) before he or she was exposed to the novel word-objects in the subsequent fast mapping task. Significant speech practice and language effects on fast mapping production scores were found. These findings suggest a complex relationship between speech learning, fast mapping, and L1-L2 language skills. Our results suggest that clinical methods that facilitate bilingual childrens production skills (e.g., repeat after a model) hold promise as a means of improving the initial stage of word learning in both languages.

The effect of noise on novel word learning in sequential bilingual children

Preschool children must learn in noisy environments (Picard and Bradley, 2001), but young children are more negatively affected by background noise than are adults (Elliott, 1979). Young second‐language learners are more negatively affected by noise than are monolingual children (Crandell et al., 1996; Nelson et al., 2005). Background noise may be still more detrimental in the case of preschool children who speak one language (L1) at home and who start to learn a second language (L2) in nursery school. In this present study we examine the effect of noise on fast‐mapping skills in L1 (Hmong) and L2 (English). In the fast‐mapping task each child was briefly presented with 5 novel wordscounterbalanced in Hmong and in English–in a quiet setting over two different sessions. Another 5 novel Hmong and English words were presented to each child in two sessions in the presence of babble background noise. During each session the children were tested immediately after their exposure to the novel words. The results c...