Dynamic assessment and word learning

This is the author's accepted manuscript. The original is available at http://www.speechpathologyaustralia.org.au/publications/jcpslpPast studies indicate that standardized vocabulary tests may be insensitive to language impairments and may be culturally biased. Dynamic assessment may be used as an alternative or supplementary approach to measure a child's ability to learn words. Factors that may need to be manipulated in dynamic assessment include phonotactic probability (i.e. frequency of sound sequences) and neighborhood density (phonological similarity) cause past research suggests that children with typical development learn common-dense sound sequences more readily than rare-sparse. Incorporating these factors into dynamic assessment is illustrated

Individual differences in the influence of phonological characteristics on expressive vocabulary development by young children

This is the author's accepted manuscript. The original is available at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=465943&fulltextType=RA&fileId=S0305000906007458The current study attempts to differentiate effects of phonotactic probability (i.e. the likelihood of occurrence of a sound sequence), neighbourhood density (i.e. the number of phonologically similar words), word frequency, and word length on expressive vocabulary development by young children. Naturalistic conversational samples for three children (age 1;4–3;1) were obtained from CHILDES. In a backward regression analysis, phonotactic probability, neighbourhood density, word frequency, and word length were entered as possible predictors of ages of first production of words for each child. Results showed that the factors affecting first production of words varied across children and across word types. Specifically, word length affected ages of first production for all three children, whereas the other three variables affected only one child each. The implications of these findings for models of expressive vocabulary development are discussed

Differentiating the effects of phonotactic probability and neighborhood density on vocabulary comprehension and production: A comparison of preschool children with versus without phonological delays

This is the author's accepted manuscript. The original publication is available at http://jslhr.pubs.asha.org/article.aspx?articleid=1781591Purpose The purpose of this study was to differentiate the effect of phonotactic probability from that of neighborhood density on a vocabulary probe administered to preschool children with or without a phonological delay. Method Twenty preschool children with functional phonological delays and 34 preschool children with typical language development completed a 121 item vocabulary probe in both an expressive and receptive response format. Words on the vocabulary probe orthogonally varied on phonotactic probability and neighborhood density but were matched on age-of-acquisition, word frequency, word length, semantic set size, concreteness, familiarity, and imagability. Results Results showed an interaction between phonotactic probability and neighborhood density with variation across groups. Specifically, the optimal conditions for typically developing children were rare phonotactic probability with sparse neighborhoods and common phonotactic probability with dense neighborhoods. In contrast, only rare phonotactic probability with sparse neighborhoods was optimal for children with phonological delays. Conclusions Rare sound sequences and sparse neighborhoods may facilitate triggering of word learning for typically developing children and children with phonological delays. In contrast, common sound sequences and dense neighborhoods may facilitate configuration and engagement for typically developing children but not children with phonological delays due to their weaker phonological and/or lexical representations

The Effect of Homonymy on Learning Correctly Articulated Versus Misarticulated Words

This is the author's accepted manuscript. The original publication is available at http://jslhr.pubs.asha.org/article.aspx?articleid=1795801Purpose The goal of the current study was to examine the effect of homonymy (learning a second meaning for a known word form vs. learning a novel meaning and novel word form) and articulation accuracy (IN vs. OUT sounds) on word learning by preschool children. An added goal was to determine whether word frequency altered the effect of homonymy on word learning. Method Twenty-nine 3- to 4-year-old children were taught homonyms and novel words. Stimuli further varied in whether homonymy was present in both the adult input and the child's output (as for IN sounds) versus present only in the child's output (as for OUT sounds). Results For IN sounds, children learned homonyms more rapidly than novel words. Moreover, the homonym advantage was modulated by word frequency, such that children learned a new meaning for a high-frequency word more accurately than they learned a new meaning for a low-frequency word. In contrast, for OUT sounds, there was no evidence that homonymy influenced learning. Conclusions Homonymy in the adult input facilitates word learning by preschool children, whereas homonymy in the child's output alone does not. This effect is captured in a usage-based model of phonology and the lexicon

A comparison of homonym and novel word learning: the role of phonotactic probability and word frequency

This study compares homonym learning to novel word learning by three- to four-year-old children to determine whether homonyms are learned more rapidly or more slowly than novel words. In addition, the role of form characteristics in homonym learning is examined by manipulating phonotactic probability and word frequency. Thirty-two children were exposed to homonyms and novel words in a story with visual support and learning was measured in two tasks: referent identification; picture naming. Results showed that responses to homonyms were as accurate as responses to novel words in the referent identification task. In contrast, responses to homonyms were more accurate than responses to novel words in the picture-naming task. Furthermore, homonyms composed of common sound sequences were named more accurately than those composed of rare sound sequences. The influence of word frequency was less straightforward. These results may be inconsistent with a one-to-one form-referent bias in word learning

The effect of incremental changes in phonotactic probability and neighborhood density on word learning by preschool children

This is the author's accepted manuscript. The original publication is available at http://jslhr.pubs.asha.org/article.aspx?articleid=1797302Purpose. Phonotactic probability or neighborhood density have predominately been defined using gross distinctions (i.e., low vs. high). The current studies examined the influence of finer changes in probability (Experiment 1) and density (Experiment 2) on word learning. Method. The full range of probability or density was examined by sampling five nonwords from each of four quartiles. Three- and 5-year-old children received training on nonword-nonobject pairs. Learning was measured in a picture-naming task immediately following training and 1-week after training. Results were analyzed using multi-level modeling. Results. A linear spline model best captured nonlinearities in phonotactic probability. Specifically word learning improved as probability increased in the lowest quartile, worsened as probability increased in the midlow quartile, and then remained stable and poor in the two highest quartiles. An ordinary linear model sufficiently described neighborhood density. Here, word learning improved as density increased across all quartiles. Conclusion. Given these different patterns, phonotactic probability and neighborhood density appear to influence different word learning processes. Specifically, phonotactic probability may affect recognition that a sound sequence is an acceptable word in the language and is a novel word for the child, whereas neighborhood density may influence creation of a new representation in long-term memory

Recurrence of neovascular age-related macular degeneration after cessation of treat and extend regimen

The appropriate timing of treatment cessation after treat and extend (TAE) regimen for age-related macular degeneration has not been established. This study aimed to investigate the incidence and risk factors of recurrence after cessation of the TAE regimen. We included patients who received and discontinued the TAE regimen, after extension of the treatment interval to ≥ 12 weeks. Forty-nine patients were included in the study. The estimated recurrence rates were 33% at 1 year and 48% at 2 years after treatment cessation, respectively. Good visual acuity at cessation and a large number of injections in the 6 months before cessation were significant risk factors. Higher chances of recurrence were associated with < 0.1 logarithm of the minimum angle of resolution (logMAR) at cessation (P < 0.002). Meanwhile, five patients with visual acuity ≥ 1.0 logMAR at cessation did not show recurrence. Among the 25 recurrences, two lines of vision loss were noted in only two cases after resumed treatment. This study confirmed the importance of the number of injections in reducing recurrence and the association between visual acuity and recurrence. Recurrence is generally well-controlled with resumed treatment

Functional tooth number and mortality

Aim: Previous studies on the association between intraoral conditions and mortality in community-dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community-dwelling Japanese older adults. Methods: This study was a retrospective, observational and population-based follow-up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow-up period was 1697.0 ± 774.5 days. The primary outcome was all-cause mortality at follow-up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured. Results: Kaplan–Meier analysis, followed by a log-rank test, revealed that fewer PT (P < 0.001) and FT (P = 0.002) were significantly associated with a reduced survival rate. Cox's proportional hazard analysis indicated that the number of FT, but not the number of PT, was a significant independent mortality risk factor after adjusting for demographics, clinical variables, nutrient markers and physical functioning (P = 0.036, hazard ratio: 2.089). Conclusions: Current results suggest that the number of FT more strongly predicts all-cause mortality than the number of PT among community-dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status

Number of functional teeth more strongly predicts all‐cause mortality than number of present teeth in Japanese older adults

Aim Previous studies on the association between intraoral conditions and mortality in community‐dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community‐dwelling Japanese older adults. Methods This study was a retrospective, observational and population‐based follow‐up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow‐up period was 1697.0 ± 774.5 days. The primary outcome was all‐cause mortality at follow‐up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured. Results Kaplan–Meier analysis, followed by a log‐rank test, revealed that fewer PT (P  Conclusions Current results suggest that the number of FT more strongly predicts all‐cause mortality than the number of PT among community‐dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status

Impact of number of functional teeth on independence of Japanese older adults

Aim To examine the relationship between the number of present and functional teeth at baseline and future incidence of loss of independence. Methods Participants were community-dwelling older individuals who participated in a comprehensive geriatric health examination conducted in Kusatsu town, Japan, between 2009 and 2015. The primary endpoint was the incidence of loss of independence among participants, defined as the first certification of long-term care insurance in Japan. The numbers of present and functional teeth at baseline were determined via an oral examination. Demographics, clinical variables (e.g., history of chronic diseases and psychosocial factors), blood nutritional markers, physical functions, and perceived masticatory function were assessed. Results This study included 1121 individuals, and 205 individuals suffered from loss of independence during the follow-up period. Kaplan–Meier estimates of loss of independence for participants with smaller numbers of present and functional teeth were significantly greater than for those with larger numbers of teeth. Cox proportional hazard analyses indicated that a smaller number of present teeth was not a significant risk factor after adjusting for demographic characteristics. However, the number of functional teeth was a significant risk factor after the adjustment (hazard ratio: 1.975 [1.168–3.340]). Additionally, higher hazard ratios were observed in other adjusted models, but they were not statistically significant. Conclusions The number of functional teeth may be more closely related to the future incidence of loss of independence than the number of present teeth. This novel finding suggests that prosthodontic rehabilitation for tooth loss possibly prevents the future incidence of this life-event