bluuebunny/crossref_metadata_2025 huggingface dataset:
Complementing Behavioral Measures With Electrophysiological Measures in Diagnostic Evaluation: A Case Study in Two Languages
Authors: Martin Jeffrey S. , Jerger James F. , Ulatowska Hanna K. , Mehta Jyutika A.
Published: May 2007

This case study focuses on a bilingual, older man who spoke Polish and English and showed weaknesses on clinical measures of dichotic listening in English. It was unclear whether these test results were influenced by the participant’s facility with his second language or by other nonauditory factors. To elucidate the nature of this deficit, the authors examined behavioral and electrophysiological responses during dichotic-listening tasks involving linguistic processing in both languages. A diotic (control) condition was included to examine whether nonauditory factors, such as language familiarity, memory, or decline in speed of mental processing, might explain the dichotic results. The results from this participant were compared with those obtained from a bilingual young adult who also spoke both Polish and English. Results showed a substantial left-ear deficit for the older individual on both behavioral and electrophysiological measures of dichotic listening. The pattern of results is consistent with previous findings in demonstrating that the left-ear deficit in this patient derived from an auditory-specific defect rather than from any of the extra-auditory factors associated with language facility or cognitive decline.
The Effects of High-Frequency Amplification on the Objective and Subjective Performance of Hearing Instrument Users With Varying Degrees of High-Frequency Hearing Loss
Authors: Plyler Patrick N. , Fleck Erica L.
Published: May 2007

Purpose

The purpose of the present study was to determine if amplifying beyond 2 kHz affected the objective and subjective performance of hearing instrument users with varying degrees of mild-to-severe high-frequency sensorineural hearing loss.

Method

Twenty participants were fitted binaurally with digital completely-in-the-canal devices with 4-channel wide dynamic range compression (Starkey Axent). Each participant used the hearing instruments for two 6-week trial periods. Each hearing instrument was programmed to maximize high-frequency audibility during 1 trial period and minimize high-frequency audibility during the other trial period. Objective evaluations were conducted in quiet using the Connected Speech Test (CST) and in noise using the CST and the Hearing in Noise Test. Subjective performance was evaluated by administering the Abbreviated Profile of Hearing Aid Benefit and a questionnaire.

Results

Results indicated that high-frequency amplification significantly improved objective performance in noise and subjective preference in quiet for listeners with varying degrees of mild-to-severe high-frequency hearing loss. Results also suggested that high-frequency amplification may affect subjective preference in noise and overall for listeners with varying degrees of mild-to-severe high-frequency hearing loss when feedback is eliminated.

Conclusion

Based on these significant benefits, dispensers should be aware that high-frequency amplification should, at least initially, be provided to the affected high-frequency regions when mild-to-severe hearing loss is present.
Influences of Electromagnetic Articulography Sensors on Speech Produced by Healthy Adults and Individuals With Aphasia and Apraxia
Authors: Katz William F. , Bharadwaj Sneha V. , Stettler Monica P.
Published: May 2007

Purpose

This study examined whether the intraoral transducers used in electromagnetic articulography (EMA) interfere with speech and whether there is an added risk of interference when EMA systems are used to study individuals with aphasia and apraxia.

Method

Ten adult talkers (5 individuals with aphasia/apraxia, 5 controls) produced 12 American English vowels in /hVd/ words, the fricative–vowel (FV) words (/si/, /su/, /ěi/, /ěu/), and the sentence
She had your dark suit in greasy wash water all year,
in EMA sensors-on and sensors-off conditions. Segmental durations, vowel formant frequencies, and fricative spectral moments were measured to address possible acoustic effects of sensor placement. A perceptual experiment examined whether FV words produced in the sensors-on condition were less identifiable than those produced in the sensors-off condition.

Results

EMA sensors caused no consistent acoustic effects across all talkers, although significant within-subject effects were noted for a small subset of the talkers. The perceptual results revealed some instances of sensor-related intelligibility loss for FV words produced by individuals with aphasia and apraxia.

Conclusions

The findings support previous suggestions that acoustic screening procedures be used to protect articulatory experiments from those individuals who may show consistent effects of having devices placed on intraoral structures. The findings further suggest that studies of fricatives produced by individuals with aphasia and apraxia may require additional safeguards to ensure that results are not adversely affected by intraoral sensor interference.
Response Time in 14-Year-Olds With Language Impairment
Authors: Miller Carol A. , Leonard Laurence B. , Kail Robert V. , Zhang Xuyang , Tomblin J. Bruce , Francis David J.
Published: May 2007

Purpose

To determine whether children with language impairment were slower than typically developing peers at age 14, and whether slowing, if present, was similar across task domains; whether differences in response time (RT) across domains were the same for children with specific language impairment (SLI) and nonspecific language impairment (NLI); and whether RT performance at age 9 predicted performance at age 14.

Method

Fourteen-year-old children with SLI (
n
= 20), NLI (
n
= 15), and typical development (NLD;
n
= 31) were administered several linguistic and nonlinguistic speeded tasks. The children had received the same tasks at age 9. RT performance was examined.

Results

Both the SLI and the NLI groups were significantly slower than the NLD group in motor, nonverbal cognitive, and language task domains, and there was no significant difference among domains. Individual analyses showed that most, but not all, children with SLI and NLI were slower than the NLD group mean. Slowing at age 9 and age 14 were moderately correlated.

Conclusions

The results suggest that slow RT is a persistent characteristic of many children with language impairment; however, the nature of the relationship between RT and language performance requires further investigation.
Perception of Individuals With Voice Disorders by Monolingual English, Bilingual Cantonese–English, and Bilingual Russian–English Women
Authors: Altenberg Evelyn P. , Ferrand Carole T.
Published: May 2007

Purpose

The purpose of this study was to examine the attitudes of monolingual English, bilingual Cantonese–English, and bilingual Russian–English speakers toward individuals with voice disorders.

Method

In a mixed experimental design, a total of 30 older and 29 younger female listeners from the 3 language groups rated the voices of 10 females, each with a mild, moderate, or severe voice disorder or with no voice disorder. A semantic differential scale was used to rate the speakers on 21 attributes.

Results

Results indicate that the perception of individuals became increasingly negative as the severity of the disorder increased. Results also indicate that Cantonese–English bilinguals rated the individuals with severe voice disorders more negatively than did English monolinguals and that the language groups differed in their ratings for the attributes of
beautiful,
lovable,
clean,
and
young.
There was no overall effect of age of listener.

Conclusion

The study demonstrates that although the language groups were uniform in ascribing more negative attributes to individuals as severity of the disorder increased, there were also significant differences between the groups. Exploration of these issues provides information useful to clinicians in setting priorities for intervention that take into account individuals' backgrounds as well as clinical factors.
Effect of Attentional State on Frequency Discrimination: A Comparison of Children With ADHD On and Off Medication
Authors: Sutcliffe Paul A. , Bishop Dorothy V. M. , Houghton Stephen , Taylor Myra
Published: May 2007

Debate continues over the hypothesis that children with language or literacy difficulties have a genuine auditory processing deficit. Several recent studies have reported deficits in frequency discrimination (FD), but it is unclear whether these are genuine perceptual impairments or reflective of the comorbid attentional problems that exist in many children with language and literacy difficulties. The present study investigated FD in children with attention deficit hyperactivity disorder (ADHD) when their attentional state was altered with stimulant medication. Auditory thresholds were obtained using FD and frequency modulation detection (FM) tasks. In the FD task, participants judged which of 2 pairs contained a high–low frequency sound, and in the FM task, children judged which of two tones “wobbled” (i.e., modulated). Children with ADHD had significantly poorer and more variable FD performance when off compared to on stimulant medication, and did significantly worse than controls on all FD runs when off but not on stimulant medication. However, children with ADHD did not differ from controls on the FM task. These findings demonstrate that certain auditory discrimination tasks are influenced by the child’s attentional status. In addition, significant relationships between FD and measures of language and reading were abolished when comorbid attentional difficulties were taken into account. The study has implications for design and interpretation of studies investigating links between auditory discrimination and difficulties in language and literacy.
Differentiating Phonotactic Probability and Neighborhood Density in Adult Word Learning
Authors: Storkel Holly L. , Armbrüster Jonna , Hogan Tiffany P.
Published: May 2007

Purpose

The purpose of this study was to differentiate effects of phonotactic probability, the likelihood of occurrence of a sound sequence, and neighborhood density, the number of words that sound similar to a given word, on adult word learning. A second purpose was to determine what aspect of word learning (viz., triggering learning, formation of an initial representation, or integration with existing representations) was influenced by each variable.

Method

Thirty-two adults were exposed to 16 nonwords paired with novel objects in a story context. The nonwords orthogonally varied in phonotactic probability and neighborhood density. Learning was measured following 1, 4, and 7 exposures in a picture-naming task. Partially correct (i.e., 2 of 3 phonemes correct) and completely correct responses (i.e., 3 of 3 phonemes correct) were analyzed together and independently to examine emerging and partial representations of new words versus complete and accurate representations of new words.

Results

Analysis of partially correct and completely correct responses combined showed that adults learned a lower proportion of high-probability nonwords than low-probability nonwords (i.e., high-probability disadvantage) and learned a higher proportion of high-density nonwords than low-density nonwords (i.e., high-density advantage). Separate analysis of partially correct responses yielded an effect of phonotactic probability only, whereas analysis of completely correct responses yielded an effect of neighborhood density only.

Conclusions

These findings suggest that phonological and lexical processing influence different aspects of word learning. In particular, phonotactic probability may aid in triggering new learning, whereas neighborhood density may influence the integration of new lexical representations with existing representations.
Evaluating the Discriminant Accuracy of a Grammatical Measure With Spanish-Speaking Children
Authors: Gutiérrez-Clellen Vera F. , Restrepo M. Adelaida , Simón-Cereijido Gabriela
Published: May 2007

Purpose

The purpose of this study was to evaluate the discriminant accuracy of a grammatical measure for the identification of language impairment in Latino Spanish-speaking children. The authors hypothesized that if exposure to and use of English as a second language have an effect on the first language, bilingual children might exhibit lower rates of grammatical accuracy than their peers and be more likely to be misclassified.

Method

Eighty children with typical language development and 80 with language impairment were sampled from 4 different geographical regions and compared using linear discriminant function analysis.

Results

Results indicated fair-to-good sensitivity from 4;0 to 5;1 years, good sensitivity from 5;2 to 5;11 years, and poor sensitivity above age 6 years. The discriminant functions derived from the exploratory studies were able to predict group membership in confirmatory analyses with fair-to-excellent sensitivity up to age 6 years. Children who were bilingual did not show lower scores and were not more likely to be misclassified compared with their Spanish-only peers.

Conclusions

The measure seems to be appropriate for identifying language impairment in either Spanish-dominant or Spanish-only speakers between 4 and 6 years of age. However, for older children, supplemental testing is necessary.
Subcategory Learning in Normal and Language Learning-Disabled Adults: How Much Information Do They Need?
Authors: Richardson Jessica , Harris Laurel , Plante Elena , Gerken LouAnn
Published: May 2007

Purpose

The purpose of this experiment was to determine if nonreferential morphophonological information was sufficient to facilitate the learning of gender subcategories (i.e., masculine vs. feminine) in individuals with normal language (NL) and those with a history of language-based learning disabilities (HLD).

Method

Thirty-two adults listened for 18 min to a familiarization set of Russian words that included either 1 (single-marked) or 2 (double-marked) morphophonological markers indicating gender. Participants were then tested on their knowledge of both trained and untrained members of each gender subcategory.

Results

Testing indicated that morphophonological information is sufficient for lexical subcategory learning in both NL and HLD groups, although the HLD group had lower overall accuracy. The HLD group benefited from double-marking relative to single-marking for subcategory learning.

Conclusion

The results demonstrated that learning through implicit mechanisms occurred after a relatively brief exposure to the language stimuli. In addition, the weaker overall learning by the HLD group was facilitated when multiple cues to linguistic subcategory were available in the input group members received.
Children’s History of Speech-Language Difficulties: Genetic Influences and Associations With Reading-Related Measures
Authors: DeThorne Laura Segebart , Hart Sara A. , Petrill Stephen A. , Deater-Deckard Kirby , Thompson Lee Anne , Schatschneider Chris , Davison Megan Dunn
Published: May 2007

Purpose

This study examined (a) the extent of genetic and environmental influences on children’s articulation and language difficulties and (b) the phenotypic associations between such difficulties and direct assessments of reading-related skills during early school-age years.

Method

Behavioral genetic analyses focused on parent-report data regarding the speech-language skills of 248 twin pairs (
M
= 6.08 years) from the Western Reserve Reading Project. In addition, phenotypic associations between children’s speech-language status and direct assessments of early reading-related abilities were examined through hierarchical linear modeling (HLM).

Results

Probandwise concordance rates and intraclass tetrachoric correlations indicated high heritability for children’s difficulties in expressive language and articulation, with estimates of .54 and .97 accordingly. HLM results indicated that children with histories of speech-language difficulties scored significantly lower than unaffected children on various measures of early reading-related abilities.

Conclusions

Results from the parent-report survey provided converging evidence of genetic effects on children’s speech and language difficulties and suggest that children with a history of speech-language difficulties are at risk for lower performance on early reading-related measures. The extent of risk differed across measures and appeared greatest for children who demonstrated a history of difficulties across articulation, expressive language, and receptive language. Implications for future genetic research and clinical practice are discussed.
Dysgraphia in Alzheimer’s Disease: A Review for Clinical and Research Purposes
Authors: Neils-Strunjas Jean , Groves-Wright Kathy , Mashima Pauline , Harnish Stacy
Published: May 2007

Purpose

This article presents a critical review of literature on dysgraphia associated with Alzheimer’s disease (AD). Research presented includes discussions of central and peripheral spelling impairments as well as the impact of general, nonlinguistic cognitive functions on dysgraphia associated with AD.

Method

The studies critically reviewed were from a variety of disciplines, with emphasis on seminal work, recent literature, and the first author’s research.

Conclusions

Studies have shown that writing impairment is heterogeneous within the AD population; however, there are certain aspects of the writing process that are more vulnerable than others and may serve as diagnostic signs. Identifying patterns of writing impairment at different stages of AD may help to chart disease progression and assist in the development of appropriate interventions.
The Effect of Hearing Loss on Identification of Asynchronous Double Vowels
Authors: Lentz Jennifer J. , Marsh Shavon L.
Published: May 2007

This study determined whether listeners with hearing loss received reduced benefits due to an onset asynchrony between sounds. Seven normal-hearing listeners and 7 listeners with hearing impairment (HI) were presented with 2 synthetic, steady-state vowels. One vowel (the late-arriving vowel) was 250 ms in duration, and the other (the early-arriving vowel) varied in duration between 350 and 550 ms. The vowels had simultaneous offsets, and therefore an onset asynchrony between the 2 vowels ranged between 100 and 300 ms. The early-arriving and late-arriving vowels also had either the same or different fundamental frequencies. Increases in onset asynchrony and differences in fundamental frequency led to better vowel-identification performance for both groups, with listeners with HI benefiting less from onset asynchrony than normal-hearing listeners. The presence of fundamental frequency differences did not influence the benefit received from onset asynchrony for either group. Excitation pattern modeling indicated that the reduced benefit received from onset asynchrony was not easily predicted by the reduced audibility of the vowel sounds for listeners with HI. Therefore, suprathreshold factors such as loss of the cochlear nonlinearity, reduced temporal integration, and the perception of vowel dominance probably play a greater role in the reduced benefit received from onset asynchrony in listeners with HI.
Effects of Increasing Sound Pressure Level on Lip and Jaw Movement Parameters and Consistency in Young Adults
Authors: Huber Jessica E. , Chandrasekaran Bharath
Published: May 2007

Purpose

Examination of movement parameters and consistency has been used to infer underlying neural control of movement. However, there has been no systematic investigation of whether the way individuals are asked (or cued) to increase loudness alters articulation. This study examined whether different cues to elicit louder speech induce different lip and jaw movement parameters or consistency.

Method

Thirty healthy young adults produced two sentences (a) at comfortable loudness, (b) while targeting 10 dB SPL above comfortable loudness on a sound level meter, (c) at twice their perceived comfortable loudness, and (d) while multitalker noise was played in the background. Lip and jaw kinematics and acoustic measurements were taken.

Results

Each of the loud conditions resulted in a similar amount of SPL increase, about 10 dB. Speech rate was slower in the background noise condition. Changes to movement parameters and consistency (relative to comfortable) were different in the targeting condition as compared to the other loud conditions.

Conclusions

The cues elicited different task demands, and therefore, different movement patterns were used by the speakers to achieve the target of increased loudness. Based on these results, cueing should be considered when eliciting increased vocal loudness in both clinical and research situations.
A Weighted Reliability Measure for Phonetic Transcription
Authors: Oller D. Kimbrough , Ramsdell Heather L.
Published: May 2007

Purpose

The purpose of the present work is to describe and illustrate the utility of a new tool for assessment of transcription agreement. Traditional measures have not characterized overall transcription agreement with sufficient resolution, specifically because they have often treated all phonetic differences between segments in transcriptions as equivalent, thus constituting an
unweighted
approach to agreement assessment. The measure the authors have developed calculates a
weighted
transcription agreement value based on principles derived from widely accepted tenets of phonological theory.

Method

To investigate the utility of the new measure, 8 coders transcribed samples of speech and infant vocalizations. Comparing the transcriptions through a computer-based implementation of the new weighted and the traditional unweighted measures, they investigated the scaling properties of both.

Results

The results illustrate better scaling with the weighted measure, in particular because the weighted measure is not subject to the floor effects that occur with the traditional measure when applied to samples that are difficult to transcribe. Furthermore, the new weighted measure shows orderly relations in degree of agreement across coded samples of early canonical-stage babbling, early meaningful speech in English, and 3 adult languages.

Conclusions

The authors conclude that the weighted measure may provide improved foundations for research on phonetic transcription and for monitoring of transcription reliability.
Children With Specific Language Impairments Perceive Speech Most Categorically When Tokens Are Natural and Meaningful
Authors: Coady Jeffry A. , Evans Julia L. , Mainela-Arnold Elina , Kluender Keith R.
Published: May 2007

Purpose

To examine perceptual deficits as a potential underlying cause of specific language impairments (SLI).

Method

Twenty-one children with SLI (8;7–11;11 [years;months]) and 21 age-matched controls participated in categorical perception tasks using four series of syllables for which perceived syllable-initial voicing varied. Series were either words or abstract nonword syllables and either synthesized or high-quality edited natural utterances. Children identified and discriminated (a) digitally edited tokens of naturally spoken “bowl”–“pole”, (b) synthesized renditions of “bowl”–“pole”, (c) natural “ba”–“pa”, and (d) synthetic “ba”–“pa”.

Results

Identification crossover locations were the same for both groups of children, but there was modestly less accuracy on unambiguous endpoints for children with SLI. Planned comparisons revealed these effects to be limited to synthesized speech. Children with SLI showed overall reduced discrimination, but these effects were limited to abstract nonword syllables.

Conclusion

Overall, children with SLI perceived naturally spoken real words comparably to age-matched peers but showed impaired identification and discrimination of synthetic speech and of abstract syllables. Poor performance on speech perception tasks may result from task demands and stimulus properties, not perceptual deficits.
Chest Wall Motion During Speech Production in Patients With Advanced Ankylosing Spondylitis
Authors: Kalliakosta Georgia , Mandros Charalampos , Tzelepis George E.
Published: May 2007

Purpose

To test the hypothesis that ankylosing spondylitis (AS) alters the pattern of chest wall motion during speech production.

Method

The pattern of chest wall motion during speech was measured with respiratory inductive plethysmography in 6 participants with advanced AS (5 men, 1 woman, age 45±8 years, Schober test 1.45±1.5 cm, Bath Ankylosing Spondylitis Functional Index [BASFI] score 6±1.7) and 6 healthy volunteers, matched for age and gender. Measurements were made with participants in the upright seated and upright standing body position.

Results

During reading in the seated and standing body positions, the rib cage wall volume displacements were smaller and abdominal wall volume displacements were larger in participants with AS than in healthy controls. There were no differences in the overall lung volume displacements recorded during the expiratory limb of reading in either body position. In the participants with AS, the rib cage remained near the end-expiratory level in both the seated and standing body position, differing from that for the control group.

Conclusion

In individuals with advanced AS, the abdomen is the primary contributor to volume displacement. In the absence of speech impairment in participants with AS, the data show the capacity of the abdomen to compensate for the decreased compliance of the rib cage.
Articulator Movement Associated With the Development of Prosodic Control in Children
Authors: Grigos Maria I. , Patel Rupal
Published: May 2007

This study explored the relationship between articulator movement and prosody in children at different developmental ages. Jaw, lower lip, and upper lip kinematics were examined in 4-, 7-, and 11-year-old children as they produced the declarative and interrogative forms of utterances “Show Bob a bot” and “Show Pop a pot.” Articulator movement differences were found between declaratives and interrogatives during the production of vowel and consonant targets. The 7- and 11-year-olds differentiated the duration and displacement of their articulator movements to distinguish between declaratives and interrogatives. Several age-related differences in movement duration between the 4-year-olds and the older participants were associated with the production of these targets. Productions of declaratives and interrogatives were not associated with any significant differences in articulator movement variability, although variability did decrease significantly with maturation. The results suggest that children modify their articulator movements to meet the prosodic and linguistic demands of the task. While 4-year-olds appear to be able to modify lip and jaw movement to mark the declarative–interrogative contrast, refinement of these movements continues throughout childhood.
Internal Versus External: Oral-Motor Performance as a Function of Attentional Focus
Authors: Freedman Skott E. , Maas Edwin , Caligiuri Michael P. , Wulf Gabriele , Robin Donald A.
Published: May 2007

Purpose

Previous studies (e.g., G. Wulf, M. Höß, & W. Prinz, 1998; G. Wulf, B. Lauterbach, & T. Toole, 1999; for a review, see G. Wulf & W. Prinz, 2001) have reported that limb motor performance is enhanced when individuals adopt an external focus (focusing on the effect of the movement) versus an internal focus of attention (focusing on body parts such as the muscles of the hand). This study tested the hypothesis that the effects of attentional focus on limb performance would also occur in the oral-facial system.

Method

Two groups of 23 participants were administered both hand and tongue impulse force control tasks in which each group was randomly assigned either an internal or an external focus of attention. Participants were required to exert rapid pressure bursts to achieve a target force level of 20% of their maximal strength.

Results

Consistent with limb studies, findings revealed a significant advantage of an external focus (greater accuracy, less variability) for both the hand and tongue control tasks, as opposed to an internal focus of attention.

Conclusions

Results are discussed relative to a constrained-action theory of motor control and future application to speech motor learning.
Conceptual Organization at 6 and 8 Years of Age: Evidence From the Semantic Priming of Object Decisions
Authors: Hashimoto Naomi , McGregor Karla K. , Graham Anne
Published: May 2007

Purpose

The purpose of this study was to examine children’s knowledge of semantic relations.

Method

In Experiment 1, the 6-year-olds, 8-year-olds, and adults participated in an object decision task. Participants in the primed group made object decisions in response to primes that were related taxonomically, thematically, or perceptually to the target objects. Those in the unprimed group made decisions about the same stimuli without the benefit of primes. In Experiment 2, the children in the primed group explained the taxonomic and thematic relations between the prime–target pairs used in Experiment 1.

Results

In Experiment 1, the strength of semantic relations did not vary with type or age, as taxonomic priming was as strong as thematic priming and the degree of priming did not reliably differentiate the 3 age groups. Differential priming effects between taxonomic and perceptual conditions, the former hastening and the latter slowing responses, suggested that the relation binding object concepts into taxonomies was not reducible to common physical features. In Experiment 2, the 6-year-olds had more difficulty describing taxonomic than thematic relations, whereas the 8-year-olds described both with ease.

Conclusions

Contrary to the shift hypothesis, taxonomic and thematic relationsstructure concepts in children as young as 6 and into adulthood. In accord with the performance hypothesis, 6-year-olds' representations of taxonomic relations are fragile and vulnerable to high task demands.
The Language Use Inventory for Young Children: A Parent-Report Measure of Pragmatic Language Development for 18- to 47-Month-Old Children
Authors: O’Neill Daniela K.
Published: May 2007

Purpose

To demonstrate the internal reliability and discriminative validity of the Language Use Inventory for Young Children (LUI; D. K. O’Neill, 2002), a newly developed parent-report measure designed to assess pragmatic language development in 18–47-month-olds.

Method

To examine internal reliability, the LUI was completed by mail by 177 parents recruited from the University of Waterloo’s Centre for Child Studies database, 175 of whom completed the LUI again within 4 weeks to assess test–retest reliability. To examine discriminative validity, 49 parents of children awaiting assessment at a local speech-language clinic and 49 parents of typically developing children recruited from the Centre for Child Studies database and matched in age and sex to the clinic group completed the LUI.

Results

Alpha values for the subscales of the LUI were at or above acceptable levels (.80–.98), and steady growth in children’s pragmatic language development was demonstrated. The study of discriminant validity revealed sensitivity and specificity levels over 95%.

Conclusions

The LUI’s internal reliability and stability were strongly supported and its sensitivity and specificity in distinguishing between typically developing and language-delayed children exceeded even the most stringent criteria of 90% accuracy.
Auditory Speech Recognition and Visual Text Recognition in Younger and Older Adults: Similarities and Differences Between Modalities and the Effects of Presentation Rate
Authors: Humes Larry E. , Burk Matthew H. , Coughlin Maureen P. , Busey Thomas A. , Strauser Lauren E.
Published: May 2007

Purpose

To examine age-related differences in auditory speech recognition and visual text recognition performance for parallel sets of stimulus materials in the auditory and visual modalities. In addition, the effects of variation in rate of presentation of stimuli in each modality were investigated in each age group.

Method

A mixed-model design was used in which 3 independent groups (13 young adults with normal hearing, 10 elderly adults with normal hearing, and 16 elderly hearing-impaired adults) listened to auditory speech tests (a sentence-in-noise task, time-compressed monosyllables, and a speeded-spelling task) and viewed visual text-based analogs of the auditory tests. All auditory speech materials were presented so that the amplitude of the speech signal was at least 15 dB above threshold through 4000 Hz.

Results

Analyses of the group data revealed that when baseline levels of performance were used as covariates in the group analyses the only significant group difference was that both elderly groups performed worse than the young group on the auditory speeded-speech tasks. Analysis of individual data, using correlations, factor analysis, and linear regression, was generally consistent with the group data and revealed significant, moderate correlations of performance for similar tasks across modalities, but stronger correlations across tasks within a modality. This suggests that performance on these tasks was mediated both by a common underlying factor, such as cognitive processing, as well as modality-specific processing.

Conclusion

Performance on measures of auditory processing of speech examined here was closely associated with performance on parallel measures of the visual processing of text obtained from the same participants. Young and older adults demonstrated comparable abilities in the use of contextual information in each modality, but older adults, regardless of hearing status, had more difficulty with fast presentation of auditory speech stimuli than young adults. There were no differences among the 3 groups with regard to the effects of presentation rate for the visual recognition of text, at least for the rates of presentation used here.
Speech Perception in MRI Scanner Noise by Persons With Aphasia
Authors: Healy Eric W. , Moser Dana C. , Morrow-Odom K. Leigh , Hall Deborah A. , Fridriksson Julius
Published: May 2007

Purpose

To examine reductions in performance on auditory tasks by aphasic and neurologically intact individuals as a result of concomitant magnetic resonance imaging (MRI) scanner noise.

Method

Four tasks together forming a continuum of linguistic complexity were developed. They included complex-tone pitch discrimination, same–different discrimination of minimal pair syllables, lexical decision, and sentence plausibility. Each task was performed by persons with aphasia (PWA) and by controls. The stimuli were presented in silence and also in the noise recorded from within the bore of a 3 Tesla MRI scanner at 3 signal-to-noise (S/N) ratios.

Results

Across the 4 tasks, the PWA scored lower than the controls, and performance fell as a function of decreased S/N. However, the rate at which performance fell was not different across the 2 listener groups in any task.

Conclusions

Depending on the relative levels of the signals and noise, the intense noise accompanying MRI scanning has the potential to severely disrupt performance. However, PWA are no more susceptible to the disruptive influence of this noise than are unimpaired individuals usually employed as controls. Thus, functional MRI data from aphasic and control individuals may be interpreted without complications associated with large interactions between scanner noise and performance reduction.
Training Effects on Speech Production Using a Hands-Free Electromyographically Controlled Electrolarynx
Authors: Goldstein Ehab A. , Heaton James T. , Stepp Cara E. , Hillman Robert E.
Published: May 2007

Purpose

The
electrolarynx (EL)
is a widely used device for alaryngeal speech, but it requires manual operation and produces voice that typically has a constant fundamental frequency. An electromyographically controlled EL (EMG-EL) was designed and implemented to provide hands-free control with dynamic pitch modulation.

Method

Three participants who underwent total laryngectomy surgery and 4 participants with normal voice were trained to produce EMG-EL speech through a multiple-baseline, successive-stage protocol. Baseline performance was established through 3 testing probes, followed by multiple hour-long training sessions.

Results

At the end of the training, all participants learned to initiate, sustain, and terminate EMG-EL activation in correspondence with articulation, and most were able to modulate the pitch to produce intonational contrasts. After completing the testing/training protocol, 1 of the 3 participants who underwent total laryngectomy was encouraged to independently use the EMG-EL at his residence. This participant sustained his performance for an additional 6 weeks and also used the EMG-EL successfully to communicate over the phone.

Conclusions

Our findings suggest that some participants with laryngectomies and vocally normal individuals can learn to produce hands-free speech using the EMG-EL device within a few hours and that significant additional gains in device control (particularly pitch modulation) are attainable through subsequent training sessions.
Electropalatographic Assessment of Tongue-to-Palate Contact Patterns and Variability in Children, Adolescents, and Adults
Authors: Cheng Hei Yan , Murdoch Bruce E. , Goozée Justine V. , Scott Dion
Published: May 2007

Purpose

To investigate the developmental time course of tongue-to-palate contact patterns during speech from childhood to adulthood using electropalatography (EPG) and a comprehensive profile of data analysis.

Method

Tongue-to-palate contacts were recorded during productions of /t/, /l/, /s/, and /k/ in 48 children, adolescents and adults (aged 6–38 years) using the Reading Electropalatograph system.

Results

A protracted course of development for lingual control was indicated, with significant changes occurring until age 11 years; the adolescent period was in turn characterized by continual refinement of articulatory control. With maturity, a reduction in the amount of palatal contact and an anterior shift in the place of articulation was evident during anterior consonant productions, whereas the tongue-back-to-palate contact pattern became more consistent for the velar stop /k/.

Conclusion

These results support that maturation of the speech motor system is nonuniform.
Speed of Processing, Working Memory, and Language Impairment in Children
Authors: Leonard Laurence B. , Ellis Weismer Susan , Miller Carol A. , Francis David J. , Tomblin J. Bruce , Kail Robert V.
Published: May 2007

Purpose

Children with language impairment (LI) often perform below the level of typically developing peers on measures of both processing speed and working memory. This study examined the relationship between these 2 types of measures and attempted to determine whether such measures can account for the LI itself.

Method

Fourteen-year-old children with LI and their typically developing peers participated in a wide range of processing speed and working memory tasks and were administered a comprehensive language test battery. Confirmatory factor analyses were used to compare 3 nested models designed to examine the dimensionality of the speed and working memory measures. A model that included a general speed factor was also evaluated.

Results

The models meeting our evaluation criteria treated speed and working memory as separable factors. Furthermore, nonverbal as well as verbal processing factors emerged from these analyses. Latent variable regression analyses showed that each of the appropriate models accounted for 62% of the variance in the children’s concurrent composite language test scores, with verbal working memory making the largest contribution.

Conclusions

These findings shed light on the relationship among different types of processing and suggest that processing factors can contribute to the understanding of language disorders.
Mechanism on brain information processing: Energy coding
Authors: Wang Rubin , Zhang Zhikang , Jiao Xianfa
Published: May 2007

According to the experimental result of signal transmission and neuronal energetic demands being tightly coupled to information coding in the cerebral cortex, the authors present a brand new scientific theory that offers a unique mechanism for brain information processing. They demonstrate that the neural coding produced by the activity of the brain is well described by the theory of energy coding. Due to the energy coding model’s ability to reveal mechanisms of brain information processing based upon known biophysical properties, they cannot only reproduce various experimental results of neuroelectrophysiology but also quantitatively explain the recent experimental results from neuroscientists at Yale University by means of the principle of energy coding. Due to the theory of energy coding to bridge the gap between functional connections within a biological neural network and energetic consumption, they estimate that the theory has very important consequences for quantitative research of cognitive function.
Manufacturing method for n-type porous silicon based on Hall effect without illumination
Authors: Lin Jia-Chuan , Lee Po-Wen , Tsai Wei-Chih
Published: May 2007

A method for the fabrication of n-type porous silicon (n-PS) is developed. The Hall effect is applied in the fabrication process. The majority carriers in n-type Si (electrons) are swept down by the Lorentz force. Enough holes continuously appear on the surface layer to participate in chemical reaction during the etching process. Illumination sources are not necessary in this method. Therefore, no illumination limit has to be concerned in the formation of deep PS layer. The morphology, porosity, and photoluminescence of the n-PS prepared by the proposed method are investigated. Strong visible photoluminescence emissions are demonstrated on n-PS at about 650nm.
Energy absorption capacity of carbon nanotubes under ballistic impact
Authors: Mylvaganam Kausala , Zhang L. C.
Published: May 2007

Carbon nanotubes have great potential applications in making ballistic-resistance materials. This letter analyzes the impact of a bullet on nanotubes of different radii in two extreme cases. For a nanotube with one end fixed, the maximum nanotube enduring bullet speed increases and the energy absorption efficiency decreases with the increase in relative heights at which the bullet strikes; these values are independent of the nanotube radii when the bullet hits at a particular relative height. For a nanotube with both ends fixed, the energy absorption efficiency reaches minimum when the bullet strikes around a relative height of 0.5.
Temperature dependent photoluminescence of single CdS nanowires
Authors: Hoang Thang Ba , Titova L. V. , Jackson H. E. , Smith L. M. , Yarrison-Rice J. M. , Lensch J. L. , Lauhon L. J.
Published: May 2007

Temperature dependent photoluminescence (PL) is used to study the electronic properties of single CdS nanowires. At low temperatures, both near band edge (NBE) PL and spatially localized defect-related PL are observed in many nanowires. The intensity of the defect states is a sensitive tool to judge the character and structural uniformity of nanowires. As the temperature is raised, the defect states rapidly quench at varying rates leaving the NBE PL which dominates up to room temperature. All PL lines from the nanowires follow closely the temperature dependent band edge, similar to that observed in bulk CdS.
Ab initio studies on Schottky barrier heights at metal gate/LaAlO3 (001) interfaces
Authors: Dong Y. F. , Mi Y. Y. , Feng Y. P. , Huan A. C. H. , Wang S. J.
Published: May 2007

Schottky barrier heights (SBHs) at metal gate/LaAlO3 (001) interfaces were studied by using ab initio calculations based on density functional theory. Three kinds of metals, Al, Rh, and Pt, were considered with various interface chemistries on LaAlO3 (001) surface. It was found that the Fermi level of metal gates is not pinned at metal gate/LaAlO3 interfaces. The SBH is largely determined by the interface chemistry. The interface metal up to three layers can ultimately decide the SBH, and the SBH at the metal gate/LaAlO3 interface can be efficiently tuned by including monolayer heterovalent metal at the interface.
Plasma flame for mass purification of contaminated air with chemical and biological warfare agents
Authors: Uhm Han S. , Shin Dong H. , Hong Yong C.
Published: May 2007

An elimination of airborne simulated chemical and biological warfare agents was carried out by making use of a plasma flame made of atmospheric plasma and a fuel-burning flame, which can purify the interior air of a large volume in isolated spaces such as buildings, public transportation systems, and military vehicles. The plasma flame generator consists of a microwave plasma torch connected in series to a fuel injector and a reaction chamber. For example, a reaction chamber, with the dimensions of a 22cm diameter and 30cm length, purifies an airflow rate of 5000lpm contaminated with toluene (the simulated chemical agent) and soot from a diesel engine (the simulated aerosol for biological agents). Large volumes of purification by the plasma flame will free mankind from the threat of airborne warfare agents. The plasma flame may also effectively purify air that is contaminated with volatile organic compounds, in addition to eliminating soot from diesel engines as an environmental application.
Spin transport in polycrystalline Sb films
Authors: Kim Seong-Hoon , Eom Jonghwa , Chang Joonyeon , Han Suk-Hee
Published: May 2007

Spin transport in polycrystalline Sb films has been studied by using NiFe∕Sb∕NiFe lateral spin valve devices. A clear spin valve effect was detected in the magnetoresistance measurements, which were carried out using a conventional four-terminal geometry. The observation of a memory effect in these results indicates that the spin valve signal originates from spin injection and detection determined by the magnetization orientations of the two ferromagnetic electrodes in the NiFe∕Sb∕NiFe device. From our analysis of the spin valve signals, the authors estimate that the spin diffusion length in the Sb film is ∼2.3μm, with an injected spin polarization across the NiFe∕Sb interface of 0.8% at 20K.
Relativistic dynamical bistability and adiabatic excitation of strong plasma waves
Authors: Polomarov Oleg , Shvets Gennady
Published: May 2007

Adiabatic evolution of the nonlinear resonantly driven dynamical system generic to a variety of plasma physics problems, including generation of large-amplitude plasma waves in a plasma beat-wave accelerator, is studied. The properties of the resonant Hamiltonian and the dynamics of its phase space for adiabatically varying parameters are considered. It is shown that the system can exhibit bistability and the Hamiltonian of a bistable system always follows the same trajectory for the adiabatically varying driver regardless of whether the system is excited or left quiescent. Descriptions of the bistability, autoresonance, and their possible combination based on the properties of the resonant Hamiltonian are given.
Structural, magnetic, and ferroelectric properties of multiferroic BiFeO3 film fabricated by chemical solution deposition
Authors: Naganuma Hiroshi , Okamura Soichiro
Published: May 2007

Polycrystalline BiFeO3 film has been fabricated by a chemical solution deposition on Pt∕Ti∕SiO2∕Si(100) substrates. A ferroelectric hysteresis loop showed a high remanent polarization of 47μC∕cm2 at room temperature. Leakage current density was on the order of 10−1A∕cm2 at 100kV∕cm, indicating the high leakage current density in the present BiFeO3 film. The leakage current mechanism could be considered as follows: Ohmic conduction at low electric field and Poole-Frenkel trap-assisted conduction appeared as the electric field increased, and space-charge-limited current started at a high electric field. Weak ferromagnetism was observed at room temperature, and magnetic coercivity increased to 0.5kOe with small remanent magnetization of 2emu∕cm3 at 10K. In order to investigate the magnetoelectric effect of the BiFeO3 film, the ferroelectric hysteresis loop was measured under the magnetic field of 5kG at room temperature.