Monthly Archives: February 2010
Extended Automatic Pointing Assistive Program—A pointing assistance program to help people with developmental disabilities improve their pointing efficiency
The latest research adopted software technology to improve pointing performance is through an Automatic Pointing Assistive Program (APAP). However, APAP has some limitations. This study evaluated whether two children with developmental disabilities would be able to improve their pointing performance through an Extended Automatic Pointing Assistive Program (EAPAP), which solves the limitations of APAP. Initially, both participants had their baseline sessions. Then intervention started with the first participant. When her performance was consolidated, new baseline and intervention occurred with the second participant. Finally, both participants were exposed to the maintenance phase, in which their pointing performance improved significantly. Data indicated that both participants improved their pointing efficiency with the use of EAPAP and remained highly successful through the maintenance phase. Results of this study showed that, with the assistance of EAPAP, participants can position targets quickly, easily and accurately, thus helping the disabled to solve their pointing problems.
Hebrew Adjectives in Later Language Text Production
The study investigates the distribution and use of adjectives in 252 texts produced by 63 Hebrew-speaking children, adolescents, and adults who were asked to tell and write a story about a personal fight or a quarrel, and to present a talk and write an expository text on the topic of school violence. All adjective types and tokens in each text were identified, counted, classified, and analyzed using semantic, morphological, and syntactic criteria. Findings show that the adjective class grows larger, richer, and more diverse with age and schooling — in lexicon, morpho-semantics, and syntax. Also, adjectives configure by text genres and modalities in ways that provide independent support for text type classification from spoken narratives, on the one hand, to written expositories, on the other. Finally, gender effects point in the direction of Hebrew-speaking girls and women employing a richer and more diverse adjective lexicon than boys and men in this study.
from First Language
Learning the Meaning of Verbs: Insights from Quechua
Largely based on observations of English-speaking children, investigators have proposed constraints on verb learning, e.g., syntactic bootstrapping, the principle of uniqueness, and innate semantic-conceptual categories. Children produce overgeneralization errors as they acquire verb meaning, and data from some languages reveal an intriguing asymmetry: children use intransitive verbs transitively, while seldom using causative-transitive verbs intransitively. This study presents experimental evidence corroborating the author’s earlier finding that Quechua-speaking children’s overgeneralization errors observe the same asymmetry. The transitive variants of change-of-state verbs were elicited from 30 Peruvian children, aged 2;8—4;11. The ensuing discussion considers how Quechua-speaking children recover from this pattern of overgeneralization in light of constraints that have been proposed for children acquiring English, which is typologically very different from Quechua.
from First Language
The Influence of Frequency and Semantic Similarity on How Children Learn Grammar
Lexically based learning and semantic analogy may both play a role in the learning of grammar. To investigate this, 5-year-old German children were trained on a miniature language (nominally English) involving two grammatical constructions, each of which was associated with a different semantic verb class.Training was followed by elicited production and grammaticality judgement tests with ‘trained verbs’ and a ‘generalization’ test, involving untrained verbs. In the ‘trained verbs’ judgement test the children were above chance at associating particular verbs with the constructions in which they had heard them. They did this significantly more often with verbs which they had heard especially frequently in particular constructions, indicating lexically based learning. There was also an interaction between frequency and semantic class (or the particular verbs). In the generalization judgement test the children were at chance overall. In the elicited production generalization test 75% of the children used the same construction for all items.
from First Language
Translation Equivalents and the Emergence of Multiple Lexicons in Early Trilingual Development
This study examines lexical differentiation in early trilingual development through an analysis of the translation equivalents (TEs) produced by a Tagalog—Spanish—English trilingual child. The child’s cumulative vocabulary between 1;4 and 2;0 was reconstructed through diary records and audio-recordings, and the extent to which phonetically distinct equivalent doublets and triplets were represented in her cumulative lexicon was examined. The results indicate that TEs were produced from early on, similarly to bilingual children. However, the amount of input heard in each language determined the number and types of equivalents acquired. Also, learning a second TE took less time than learning a first, suggesting that the initial differentiation of the lexicon as evidenced by doublets might facilitate the emergence of multiple lexical systems.
from First Language
Developing Noun Phrase Complexity at School Age: A Text-Embedded Cross-Linguistic Analysis
Development of noun phrase structure and use is analyzed as an important facet of syntactic acquisition from middle childhood to adolescence. Noun phrases occurring in narrative and expository texts produced in both speech and writing by 96 native speakers of English and Hebrew were identified and examined by a set of specially devised criteria including length in words, syntactic depth, abstractness of head nouns, and nature of modifiers. Results reveal a clear and consistent developmental increment in NP complexity from age 9 to 12, and particularly from age 16 years; written expository texts emerge as a favored site for use of syntactically complex constructions; and nominal elements play a more central role in the discursive syntax of Hebrew than English. Findings are discussed in terms of the interplay between psycholinguistic factors of cognitive processing constraints and the impact of increased literacy in later language development.
from First Language
Narrative skills following early confirmation of permanent childhood hearing impairment
Results Compared with those with late-confirmed PCHI, children with early-confirmed PCHI used significantly more sentences (mean difference 2.7; 95% confidence interval [CI] 0.49–5.24; p=0.019) and categories of high-pitched morphological markers (mean difference 6.64; 95% CI 1.96–11.31; p=0.006). The number of categories of low-pitched morphological markers, phonological simplifications, and sentences with multiple clauses did not differ between groups. The odds ratios (95% CI) of superior narrative structure and narrative content in children whose PCHI was confirmed early were 3.03 (1.09–8.46; p=0.034) and 4.43 (1.52–12.89; p=0.006) respectively. Interpretation: Early confirmation compared with late confirmation of PCHI was associated with benefit to narrative skills and to certain expressive aspects of syntax and morphology, but not expressive phonology.
Language acquisition in premature and full-term infants
We tested healthy preterm (born near 28 ± 2 weeks of gestational age) and full-term infants at various different ages. We compared the two populations on the development of a language acquisition landmark, namely, the ability to distinguish the native language from a rhythmically similar one. This ability is attained 4 months after birth in healthy full-term infants. We measured the induced gamma-band power associated with passive listening to (i) the infants’ native language (Spanish), (ii) a rhythmically close language (Italian), and (iii) a rhythmically distant language (Japanese) as a marker of gains in language discrimination. Preterm and full-term infants were matched for neural maturation and duration of exposure to broadcast speech. We found that both full-term and preterm infants only display a response to native speech near 6 months after their term age. Neural maturation seems to constrain advances in speech discrimination at early stages of language acquisition.
from the Proceedings of the National Academy of Sciences of the United States of America
Mechanical amplification by hair cells in the semicircular canals
Sensory hair cells are the essential mechanotransducers of the inner ear, responsible not only for the transduction of sound and motion stimuli but also, remarkably, for nanomechanical amplification of sensory stimuli. Here we show that semicircular canal hair cells generate a mechanical nonlinearity in vivo that increases sensitivity to angular motion by amplification at low stimulus strengths. Sensitivity at high stimulus strengths is linear and shows no evidence of amplification. Results suggest that the mechanical work done by hair cells contributes ∼97 zJ/cell of amplification per stimulus cycle, improving sensitivity to angular velocity stimuli below ∼5°/s (0.3-Hz sinusoidal motion). We further show that mechanical amplification can be inhibited by the brain via activation of efferent synaptic contacts on hair cells. The experimental model was the oyster toadfish, Opsanus tau. Physiological manifestation of mechanical amplification and efferent control in a teleost vestibular organ suggests the active motor process in sensory hair cells is ancestral. The biophysical basis of the motor(s) remains hypothetical, but a key discriminating question may involve how changes in somatic electrical impedance evoked by efferent synaptic action alter function of the motor(s).
from the Proceedings of the National Academy of Sciences of the United States of America
The effect of psychosocial stimulation on cognition and behaviour at 6 years in a cohort of term, low-birthweight Jamaican children
Among the LBW-T children performance IQ scores were higher in the intervention group than in the control group (regression coefficient [B] 4.06, 95% confidence interval [CI] 0.01–7.98) as were visual–spatial memory scores (B 1.12, 95% CI 0.45–1.87). Children in the intervention group also exhibited fewer behavioural difficulties (B −2.21, 95% CI −4.13 to −0.10) than children in the control group. Compared with NBW children, LBW-T children in the control group had poorer selective attention (B=−3.35, 95% CI −5.59 to −1.26) and visual–spatial memory (B=−0.76, 95% CI −1.54 to 0.00), but there were no differences in IQ, language, or behaviour.
Stimulation had sustained benefits in LBW-T infants. Finding few differences between LBW-T and NBW school-aged children concurs with results from other developing countries.
Electrical Recording of Otoacoustic Emission
Conclusion: Otoacoustic emissions (OAEs) could be detectable as cochlear AC potentials. Spontaneous otoacoustic emissions (SOAEs) were detected either electrically or acoustically, while evoked otoacoustic emissions (EOAEs) could be detected electrically but not acoustically. Objective: Many lines of evidence support the hypothesis that SOAEs are produced by spontaneous mechanical oscillation within the cochlea, and perhaps motile properties of the outer hair cells. If this is the case, SOAEs, emitted acoustically in the external auditory meatus, could also be recorded electrically as cochlear AC potential. EOAE is also thought to be produced by vibration of the basilar membrane, generated by the backward-traveling waves. EOAE thus seems to be detectable electrically as cochlear AC potential. In the present study, SOAE and EOAE were recorded both acoustically and electrically in the guinea pigs to examine the correlation between electrically recorded SOAE (ER-SOAE) and acoustically recorded SOAE (AR-SOAE). In addition, a microphonics response (MPR) to tone pip was recorded to analyze the characteristics of the non-linear component and linear component of the AC responses. Results: (1) In 4 out of 20 guinea pigs (20%), SOAE could be detected both acoustically and electrically. (2) Electrical signals of SOAE had a better S/N ratio than acoustical signals. Generally, only some ER-SOAE could be detected acoustically. (3) Almost without exception, the prominent frequencies of multiple ER-SOAEs corresponded to the intermodulation distortion product, or harmonics. (4) ER-SOAEs were suppressed by hypoxia or intense sound exposure and reappeared upon rebreathing or discontinuation of the external tone. During recovery, prominent frequencies showed a transient downward shift in frequency. (5) SOAEs were synchronized in phase with an external tone in the spectral neighborhood of SOAE. The averaged waveform of SOAE synchronized with the external tone was the same with either acoustic or electrical signals. (6) The MPR to tone pip is composed of two components with different frequency characteristics and input/output functions. (7) The non-linear component delayed to cochlear microphonics was markedly saturated at the intensity level of 40 dB peak equivalent SPL. This component was a phase-lock response, not a frequency-locked one. (8) The non-linear component could be separated with Probst’s non-linear differential extraction technique. In the MPR to a 4-kHz tone pip, high-cut filtration at 3.5 kHz produced a waveform similar to the non-linear component separated by Probst’s method.
from ORL -Journal for Oto-Rhino-Laryngology and Its Related Specialties
Electrocochleographic and Pure-Tone Audiometric Findings in Contralateral Ear of Unilateral Acoustic Neurinoma
Conclusion: These results suggest that any size of acoustic neurinoma may affect contralateral electrocochleographic findings. One possible cause may be dysfunction of the olivocochlear efferent system and another may be endolymphatic hydrops (e.g. delayed endolymphatic hydrops). Currently, however, the causes of –SP/AP ratio increase are still unknown and further investigations are required.
from ORL -Journal for Oto-Rhino-Laryngology and Its Related Specialties
Long-Term Courses of Hearing Loss in Young Children
Conclusions: Hearing loss often progressed bilaterally. There were two progression patterns: rapid aggravation during early childhood, followed by gradual aggravation, and gradual aggravation over the entire course. The aggravation of hearing may be associated with the degree of impairment and vulnerability of the auditory organs.
from ORL -Journal for Oto-Rhino-Laryngology and Its Related Specialties
Narrow-Band Evoked Oto-Acoustic Emission from Ears with Normal and Pathologic Conditions
Conclusion: Evoked oto-acoustic emission (EOAE), in particular the slow component, is fragile with the inner ear lesions and is apt to disappear in impaired ears. This presence is thought to mean that inner ear is not badly damaged, and that the presence of EOAEs in early stage sudden deafness carries a good prognosis. Narrow-band EOAE analysis would open a potentially promising way to manage sensorineural deafness. Objective: The aim of present study was to evaluate the characteristics of EOAEs from pathologic ears by a narrow-band EOAE analysis, which allowed us to investigate amplitude, frequency content and latency of EOAEs simultaneously and also to easily detect weak echoes in cases with inner ear lesions. Materials and Methods: EOAEs were analyzed by investigating narrow-band frequency contents of EOAEs, filtered by a 100-Hz step of pass bandwidth in frequency regions from 1.0 to 2.0 kHz, and by 500 Hz of pass bandwidth in the frequency ranges of 0.5–1.0 and 2.0–5.0 kHz. EOAE testing was performed in 40 normal ears and 111 ears with pathologic disorders, including sudden deafness, Ménière’s disease and surgically proven acoustic neurinomas. Spontaneous oto-acoustic emission was investigated in some cases. In acoustic neurinoma, especially computed tomography scan and magnetic resonance imaging tests were performed to assess the tumor size. Results: (1) Narrow-band EOAE analysis revealed that EOAEs from normal ears were composed of two main echo trains and several sub-echoes. The main echo trains were divided into a fast component with a short latency of 10 ms. (2) EOAEs could often be detected from ears with moderate to severe hearing loss >45 dB HL in early stage sudden deafness. The prognosis of sudden deafness was good in cases where both a fast component and slow component were detected in the acute stage within 2 weeks after the deafness onset, and was pessimistic, when either or both of them failed to recover. (3) In Ménière’s disease, EOAE was found in 6 (40%) of 15 cases with hearing loss >50 dB, and detected in 54 (90%) of 60 cases with slight to moderate deafness <50 dB HL. Echo duration tended to become shorter, and the slow component decreased in amplitude even in ears with slight deafness <30 dB. The detection threshold of the slow component was also elevated. In ears with more advanced deafness, the slow component disappeared and only the fast component with short latency persisted. Ultimately, the fast component also faded out if the hearing was severely impaired. (4) EOAEs were detectable in 20 (95.2%) of 21 ears with surgically proven acoustic neurinoma, 16 of which had both the slow and fast components. The echo pattern of acoustic neurinoma was basically similar to that of normal ears, but the detection threshold was elevated to a varying degree, although there were some cases with much better detection threshold as compared with severe deafness.
from ORL -Journal for Oto-Rhino-Laryngology and Its Related Specialties
A Path Analysis of Reading Comprehension for Adults With Low Literacy
Adult literacy interventions often rely on models of reading validated with children or adult populations with a broad range of reading abilities. Such models do not fully satisfy the need for intervention research and development for adults with low literacy. Thus, the authors hypothesized that a model representing the relationship between reading component skills would be predictive of reading comprehension for an adult population with low literacy and beneficial to adult literacy researchers. Using data from 174 adults participating in adult basic education and secondary education programs, the authors performed a path analysis of component skills’ contribution to reading comprehension. The findings are clear that existing reading models do not describe this population. The implications are discussed in terms of instructional and curricular interventions.
from the Journal of Learning Disabilities
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