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Biomedical subjects

J A Till

Publications and source records attributed to J A Till.

29 records · Page 2Linked to original sources
PubMed1988

Acoustic phonetic effects of two types of verbal feedback in dysarthric subjects.

The effects of two different forms of verbal feedback on speech production were studied in 7 dysarthric speakers. Both forms of verbal feedback signaled that the listener failed to understand the message. The more general form of feedback gave no specific cues regarding the reason the listener failed to understand. The more specific feedback indicated that a voiceless initial consonant was perceived as its voiced cognate. The subjects studied had inconsistent voicing errors. Voice onset times (VOTs) and syllabic intensity, duration, and rate were measured in the phrases produced prior to and after verbal feedback. The results showed a significant change in VOT after the specific feedback and no significant change in VOT after the more general feedback. The use of specific feedback to induce articulatory change during speech treatment is discussed.

Adult↗
PubMed1987

Effects of auditory feedback and phonetic context on stomal noise in laryngectomized speakers.

Stomal noise intensity during esophageal speech was measured in 7 laryngectomized subjects during amplified monaural auditory feedback and during control conditions without feedback. A significant (5-10 dB) reduction in stomal noise was observed when auditory feedback was applied. The conditions without feedback were designed to provide additional information regarding the effects of the initial phonetic element in the esophageal speech token on stomal noise. During the control conditions, esophageal speech tokens beginning with voiceless consonants resulted in significantly more stomal noise than was present for the other speech tokens. Clinical implications of the findings are discussed.

Aged↗
PubMed1987

Is oxygen supply the only regulator of erythropoietin levels? Serum immunoreactive erythropoietin during the first 4 months of life in term infants with different levels of arterial oxygenation.

Serum immunoreactive erythropoietin (siEp) levels were measured in 35 full-term infants aged 0-13 weeks, 31 of whom had congenital heart disease. The infants displayed a wide range in arterial oxygen tension (PaO2) and oxygen saturation (SaO2). During the first days of life siEp varied widely with a range from less than 3 to more than 10,000 mIU/ml. The wide variation is consistent with findings in cord blood at term. The siEp levels did not correlate significantly with haemoglobin, haematocrit, PaO2, SaO2, or arterial oxygen content in the total sample, nor when the cohort was split up into different age groups. Cyanotic infants aged 2-13 weeks had significantly higher siEp concentrations than normal adults (p less than 0.001) and than children with cyanotic congenital heart disease, aged 4 months-10 years (p less than 0.001). The raised siEp levels in cyanotic children aged 2-13 weeks found in this study and the normal levels found in their older counterparts (4 months-10 years) (reported elsewhere) are consistent with the pattern observed in man and animals exposed to prolonged hypobaric hypoxia, in which after an initial rise in erythropoietin concentrations the levels fall to normal while increased erythropoiesis is sustained.

Cross-Sectional Studies↗
PubMed1987

Treatment of refractory supraventricular arrhythmias with flecainide acetate.

We treated 13 children aged 0.2 years to 15.7 years (median 7.1 years) with flecainide acetate for refractory symptomatic supraventricular tachycardia. Six children had direct atrioventricular accessory pathways, of whom four had overt Wolff-Parkinson-White syndrome on the 12 lead electrocardiogram, while in the other two the accessory pathway was concealed. Three children had nodal atrioventricular re-entrant tachycardia, two had a re-entrant tachycardia, the exact mechanism of which was not known, one child had ectopic atrial tachycardia, and one had atrial flutter associated with an atrial septal defect. The remaining 12 children had structurally normal hearts. Flecainide (2 mg/kg intravenously) resulted in termination of the tachycardia in 11 of the 12 children treated during tachycardia. In 11 of the children successful prophylaxis was achieved with oral flecainide. Side effects occurred in two children during intravenous administration, but there were no side effects with oral treatment. This experience indicates that flecainide, which has not been used extensively in children, is an effective and safe antiarrhythmic agent, capable of terminating and controlling supraventricular tachycardia in children. Furthermore, flecainide may be successful where conventional agents fail.

Administration, Oral↗
PubMed1987

Serum immunoreactive erythropoietin in children with cyanotic and acyanotic congenital heart disease.

Serum immunoreactive erythropoietin (siEp) was measured in 27 cyanotic and 21 acyanotic children with congenital heart disease, age 4 months to 10 years. The geometric mean value was 9 mIU/mL for each group with 95% range from 3 to 26 mIU/mL and 4 to 22 mIU/mL for the cyanotic and acyanotic subjects, respectively. The levels are similar to those found in normal adults using the same assay system. Three cyanotic subjects showed increased siEp values. One was anemic relative to his hypoxemia, and the other two showed signs of increasing hypoxia. There was a significant negative correlation between siEp and arterial oxygen content. However, siEp did not correlate significantly with hemoglobin, hematocrit, PaO2, or SaO2. Despite normal siEp levels, the cyanotic children showed compensatory erythropoiesis with significantly elevated hemoglobin and hematocrit levels, which did correlate inversely with PaO2 and SaO2. Arterial oxygen content was also significantly higher in the cyanotic subjects (p less than 0.02). The cyanotic children seemed to display the same pattern as observed in man and animals exposed to prolonged hypobaric hypoxia, where after an initial rise in erythropoietin values the levels fall to normal, while increased erythropoiesis is sustained.

Arteries↗
PubMed1983

Phonatory and manual reaction times of stuttering and nonstuttering children.

This investigation compared the simple reaction times of 13 stuttering and 13 nonstuttering children matched individually for age, sex, and handedness. The reaction time stimulus in all response conditions was the offset of a 1000-Hz pure tone. Two of the experimental conditions required button-pressing responses, one using the left forefinger and the other the right. The remaining four experimental conditions required phonatory responses. The nonspeech phonatory responses consisted of inspiratory phonation and expiratory throat clearing; the speech-like phonatory responses required abrupt initiation of the isolated vowel and the word upper. The stuttering children were slower and more variable than the normal children only during phonatory initiation of throat clearing and. The results are compared to previous reaction time investigations with both children and adults and related to certain factors which potentially can influence sensorimotor pathways prior to and during speech.

Child↗
PubMed1982

A comparison of two procedures to elicit verbal auxiliary and copula in normal kindergarten children.

Fourteen normal kindergarten children, all of whom spontaneously used verbal auxiliary and copular forms of BE (VACs) were studied. Two cloze procedures were designed to elicit all three forms of present tense VACs in uncontractible sentence positions. The syntactic elicitation (SE) procedure required the children to observe a syntactic constraint within a descriptive response; the emphatic elicitation (EE) procedure required observation of a stress constraint within a role-playing response. Personal pronouns were used as sentence subjects in both procedures. Results indicated that both procedures were effective in eliciting VACs approximately 75% of the time. The SE procedure was more effective than the EE procedure overall. The procedures did not differ in their ability to elicit auxiliary and copular forms. The effects of subject pronoun person and singular vs. plural verb form are discussed. The procedures have implications for supplementing spontaneous language samples in assessing expressive language.

Child↗
PubMed1982

Morphophonemic rule learning in normal and articulation-disordered children.

This study investigated the phonological learning abilities of articulation-disordered children. Eight normally speaking and eight articulation-disordered kindergarten children were taught an artificial morphophonemic rule. The rule required the subjects to extract and organize phonological information by differentiating among the critical features of stop and fricative consonants. A miniature artificial language paradigm was used to teach the rule by auditorily presenting a limited number of examples of the rule and measuring generalization to untaught items. The groups were compared to determine if they differed in rate or accuracy of learning and generalization of the correct response. Individual patterns of learning were also examined. Results revealed essentially no differences in the way the two groups learned the stop class. In contrast, the disordered children incorporated fricatives into the rule more quickly than the normal children did. In addition, there was a trend for the disordered children to respond with more accuracy ad more generalized responses to the fricatives. This trend was unexpected and is discussed in terms of a sensitive period for learning phonological information.

Articulation Disorders↗
PubMed1981

Instrumentation and validity for direct-readout voice onset time measurement.

Methods and instrumentation for direct readout of voice onset time (VOT) are presented along with sample measurements for three subjects. Mean VOT and intrasubject variability are compared with data obtained from wide-band spectrograms. The results suggest that the instrumentation described yields VOT values comparable to those obtained from wide-band spectrograms. Implications for diagnosis are discussed and research needs are identified.

Adult↗
PubMed1980

Acquisition of a verb-subject-object miniature linguistic system by adults.

Two experiments are reported. In the first, ten college-aged adults were exposed to a miniature linguistic system (MLS) and the referents it encoded. The referents included three shapes which functioned as subjects in the MLS, three shapes which functioned as objects, and three actions which functioned as verbs. Nine nonsense syllables were assigned to the referents. The MLS allowed only sentences of the form, verb-subject-object, to describe a subject-shape acting in a specific manner on an object-shape. Videotaped presentations of the shape and action referents and simultaneous auditory presentation of the appropriate MLS sentence were used during teaching trials. Testing trials containing no auditory presentations were alternated with the teaching trials. During testing trials, subjects were required to write MLS sentences to describe the shape-action referents presented. The data gathered during testing trials allowed the acquisition of each lexical item, each word-class, and the word-class ordering rule to be examined. The results of Experiment I showed that the actions were learned more quickly than either the subject-shapes or the object-shapes. Experiment II investigated possible reasons for the verb-learning advantage noted in Experiment I. Twelve college-aged adults learned shape names and action names as single word responses. The results of Experiment II suggest that the verb-learning advantage noted in Experiment I was due, at least in part, to a lexical learning effect rather than a syntactical learning effect, nonsense syllable mediation, or word position. Error analyses of Experiment I data support this conclusion. Implications of the findings and the experimental technique for language remediation are discussed.

Adult↗