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PubMed2003

Acoustic and perceptual evaluation of Mandarin tone productions before and after perceptual training.

Training American listeners to perceive Mandarin tones has been shown to be effective, with trainees' identification improving by 21%. Improvement also generalized to new stimuli and new talkers, and was retained when tested six months after training [Y. Wang et al., J. Acoust. Soc. Am. 106, 3649-3658 (1999)]. The present study investigates whether the tone contrasts gained perceptually transferred to production. Before their perception pretest and after their post-test, the trainees were recorded producing a list of Mandarin words. Their productions were first judged by native Mandarin listeners in an identification task. Identification of trainees' post-test tone productions improved by 18% relative to their pretest productions, indicating significant tone production improvement after perceptual training. Acoustic analyses of the pre- and post-training productions further reveal the nature of the improvement, showing that post-training tone contours approximate native norms to a greater degree than pretraining tone contours. Furthermore, pitch height and pitch contour are not mastered in parallel, with the former being more resistant to improvement than the latter. These results are discussed in terms of the relationship between non-native tone perception and production as well as learning at the suprasegmental level.

Adolescent↗

PubMed1991

Training Japanese listeners to identify English /r/ and /l/: a first report.

Native speakers of Japanese learning English generally have difficulty differentiating the phonemes /r/ and /l/, even after years of experience with English. Previous research that attempted to train Japanese listeners to distinguish this contrast using synthetic stimuli reported little success, especially when transfer to natural tokens containing /r/ and /l/ was tested. In the present study, a different training procedure that emphasized variability among stimulus tokens was used. Japanese subjects were trained in a minimal pair identification paradigm using multiple natural exemplars contrasting /r/ and /l/ from a variety of phonetic environments as stimuli. A pretest-posttest design containing natural tokens was used to assess the effects of training. Results from six subjects showed that the new procedure was more robust than earlier training techniques. Small but reliable differences in performance were obtained between pretest and posttest scores. The results demonstrate the importance of stimulus variability and task-related factors in training nonnative speakers to perceive novel phonetic contrasts that are not distinctive in their native language.

Adult↗

PubMed1986

Vibrotactile perception of suprasegmental features of speech: a comparison of single-channel and multichannel instruments.

The recognition of three suprasegmental aspects of speech--the number of syllables in a word, the stress pattern of a word, and rising or falling intonation patterns--through a single-channel tactile device and through a 24-channel tactile vocoder, using two groups of normal-hearing subjects, was compared. All subjects received an initial pretest on three recognition tasks, one for each prosodic feature. Half the subjects from each group then received 12 h of training with feedback on the tasks and stimuli used in the pretest. All subjects received a post-test which contained physically different stimuli from those previously tested. Performance was significantly better on the syllable-number and syllabic stress tasks with the single-channel than with the multichannel device on both the pre- and post-tests; no difference was found for the intonation task. Performance on the post-test was poorer for all trained subjects compared to their final training results, suggesting that cues learned in training were not readily transferable to new stimuli, even those with similar prosodic characteristics. Overall, the results provide support for the notion that certain prosodic features of speech may be conveyed more readily when the waveform envelope is preserved.

Adult↗

PubMed1993

Training Japanese listeners to identify English /r/ and /l/. II: The role of phonetic environment and talker variability in learning new perceptual categories.

Two experiments were carried out to extend Logan et al.'s recent study [J. S. Logan, S. E. Lively, and D. B. Pisoni, J. Acoust. Soc. Am. 89, 874-886 (1991)] on training Japanese listeners to identify English /r/ and /l/. Subjects in experiment 1 were trained in an identification task with multiple talkers who produced English words containing the /r/-/l/ contrast in initial singleton, initial consonant clusters, and intervocalic positions. Moderate, but significant, increases in accuracy and decreases in response latency were observed between pretest and posttest and during training sessions. Subjects also generalized to new words produced by a familiar talker and novel words produced by an unfamiliar talker. In experiment 2, a new group of subjects was trained with tokens from a single talker who produced words containing the /r/-/l/ contrast in five phonetic environments. Although subjects improved during training and showed increases in pretest-posttest performance, they failed to generalize to tokens produced by a new talker. The results of the present experiments suggest that variability plays an important role in perceptual learning and robust category formation. During training, listeners develop talker-specific, context-dependent representations for new phonetic categories by selectively shifting attention toward the contrastive dimensions of the non-native phonetic categories. Phonotactic constraints in the native language, similarity of the new contrast to distinctions in the native language, and the distinctiveness of contrastive cues all appear to mediate category acquisition.

Acoustic Stimulation↗

PubMed1994

Training Japanese listeners to identify English /r/ and /l/. III. Long-term retention of new phonetic categories.

Monolingual speakers of Japanese were trained to identify English /r/ and /l/ using Logan et al.'s [J. Acoust. Soc. Am. 89, 874-886 (1991)] high-variability training procedure. Subjects' performance improved from the pretest to the post-test and during the 3 weeks of training. Performance during training varied as a function of talker and phonetic environment. Generalization accuracy to new words depended on the voice of the talker producing the /r/-/l/ contrast: Subjects were significantly more accurate when new words were produced by a familiar talker than when new words were produced by an unfamiliar talker. This difference could not be attributed to differences in intelligibility of the stimuli. Three and six months after the conclusion of training, subjects returned to the laboratory and were given the post-test and tests of generalization again. Performance was surprisingly good on each test after 3 months without any further training: Accuracy decreased only 2% from the post-test given at the end of training to the post-test given 3 months later. Similarly, no significant decrease in accuracy was observed for the tests of generalization. After 6 months without training, subjects' accuracy was still 4.5% above pretest levels. Performance on the tests of generalization did not decrease and significant differences were still observed between talkers. The present results suggest that the high-variability training paradigm encourages a long-term modification of listeners' phonetic perception. Changes in perception are brought about by shifts in selective attention to the acoustic cues that signal phonetic contrasts. These modifications in attention appear to be retrained over time, despite the fact that listeners are not exposed to the /r/-/l/ contrast in their native language environment.

Female↗

PubMed1997

Training Japanese listeners to identify English /r/ and /l/: IV. Some effects of perceptual learning on speech production.

This study investigated the effects of training in/r/-/l/ perceptual identification on /r/-/l/ production by adult Japanese speakers. Subjects were recorded producing English words that contrast /r/ and /l/ before and after participating in an extended period of /r/-/l/ identification training using a high-variability presentation format. All subjects showed significant perceptual learning as a result of the training program, and this perceptual learning generalized to novel items spoken by new talkers. Improvement in the Japanese trainees' /r/-/l/ spoken utterances as a consequence of perceptual training was evaluated using two separate tests with native English listeners. First, a direct comparison of the pretest and post-test tokens showed significant improvement in the perceived rating of /r/ and /l/ productions as a consequence of perceptual learning. Second, the post-test productions were more accurately identified by English listeners than the pretest productions in a two-alternative minimal-pair identification procedure. These results indicate that the knowledge gained during perceptual learning of /r/ and /l/ transferred to the production domain, and thus provides novel information regarding the relationship between speech perception and production.

Adult↗

PubMed1999

Training American listeners to perceive Mandarin tones.

Auditory training has been shown to be effective in the identification of non-native segmental distinctions. In this study, it was investigated whether such training is applicable to the acquisition of non-native suprasegmental contrasts, i.c., Mandarin tones. Using the high-variability paradigm, eight American learners of Mandarin were trained in eight sessions during the course of two weeks to identify the four tones in natural words produced by native Mandarin talkers. The trainees' identification accuracy revealed an average 21% increase from the pretest to the post-test, and the improvement gained in training was generalized to new stimuli (18% increase) and to new talkers and stimuli (25% increase). Moreover, the six-month retention test showed that the improvement was retained long after training by an average 21% increase from the pretest. The results are discussed in terms of non-native suprasegmental perceptual modification, and the analogies between L2 acquisition processes at the segmental and suprasegmental levels.

Adult↗

PubMed1993

The effect of boron supplementation on lean body mass, plasma testosterone levels, and strength in male bodybuilders.

The effect of boron supplementation was investigated in 19 male bodybuilders ages 20-27 years. Ten were given a 2.5-mg boron supplement while 9 were given a placebo every day for 7 weeks. Plasma total and free testosterone, plasma boron, lean body mass, and strength measurements were determined on Days 1 and 49 of the study. Plasma boron values were significantly (p < 0.05) different as the experimental group increased from (+/- SD) 20.1 +/- 7.7 ppb pretest to 32.6 +/- 27.6 ppb posttest, while the control group mean decreased from 15.1 +/- 14.4 ppb pretest to 6.3 +/- 5.5 ppb posttest. Analysis of variance indicated no significant effect of boron supplementation on any of the dependent variables. Both groups demonstrated significant increases in total testosterone, lean body mass, 1-RM squat, and 1-RM bench press. The findings suggest that 7 weeks of bodybuilding can increase total testosterone, lean body mass, and strength in lesser trained bodybuilders, and that boron supplementation had no effect on these measures.

Adult↗

PubMed2004

Practical implementation of a multiplex PCR for acute respiratory tract infections in children.

Molecular testing for acute respiratory infections (ARIs) has documented value but limited implementation due to questions that typically slow the acceptance of new tests. This study sought to address these questions and achieve implementation. Rhinovirus was added to a nested multiplex PCR (M-PCR), increasing its diagnostic yield. Over one winter, three hospital pediatric departments used the M-PCR to complement their direct fluorescent-antibody assay (DFA) for respiratory syncytial virus (RSV). Clinicians recorded "pretest probability estimates" (using continuous scales for various pathogen groups) for comparison with test results; treatments and test turnaround times were also recorded. Transnasal and throat swabs, with or without nasopharyngeal aspirate (NPA), were M-PCR tested. NPA-containing sample sets found to be RSV positive by DFA were not further tested. Single PCR for human metapneumovirus (hMPV) was performed retrospectively. Of 178 ARI episodes representing 172 patients, NPA was included in 97 sample sets; 54 (56%) were determined to be RSV positive. The other NPA-containing sample sets (n = 43) yielded 27 findings (63%), and the swab-only sets (n = 81) yielded 47 findings (58%); rhinovirus was found most often. Testing for hMPV yielded seven positive results. M-PCR median turnaround times were 4 days in swab-only samples and 5 days with NPA. Antibiotics were prescribed in 50 episodes, at rates similar for RSV and rhinovirus. Pretest probability estimates of a viral cause were lower in episodes caused by rhinovirus than in episodes caused by RSV. The hospitals continued to use M-PCR for NPA-containing samples found to be RSV negative by DFA. Test implementation is more likely with higher diagnostic yield and a protocol that reflects day-to-day clinical and laboratory operations.

Acute Disease↗

PubMed1987

Campaign against AIDS in Switzerland: evaluation of a nationwide educational programme.

The campaign against the spread of the acquired immune deficiency syndrome (AIDS) in Switzerland includes a nationwide educational programme. A booklet about AIDS was mailed to every Swiss household in March 1986, and in 1987 there has been a mass media campaign promoting the use of condoms. We evaluated the results of the first phase--the distribution of the booklet--using a separate sample pretest and post-test design. The pretest was carried out 15 days before the booklet was mailed (sample n = 1056) and the post-test two months after the booklet was mailed (n = 1278). Of the population aged 20-69, to whom the book was sent, 56% read the booklet. For those who read the booklet compared with those who did not the results showed an improvement in knowledge and a better understanding of the risks of specific behaviours and of exposed groups and thus less fear of becoming infected through daily activities. The mean indices of knowledge and beliefs were significantly different when tested by the Kruskal-Wallis method. Having better information does not imply that people will change their behaviour, but both the high reading rate and the increase in knowledge suggest that the Swiss educational programme reached its objectives. Moreover, the success of this campaign helps to support other campaigns that are being developed to promote the use of condoms.

Acquired Immunodeficiency Syndrome↗

PubMed1999

Cost effectiveness analysis of antenatal HIV screening in United Kingdom.

OBJECTIVE: To assess the cost effectiveness of universal antenatal HIV screening compared with selective screening in the United Kingdom. DESIGN: Incremental cost effectiveness analysis relating additional costs of screening to life years gained. Maternal and paediatric costs and life years were combined. SETTING: United Kingdom. MAIN OUTCOME MEASURES: Number of districts for which universal screening would be cost effective compared with selective screening under various conditions. RESULTS: On base case assumptions, a new diagnosis of a pregnant woman with HIV results in a gain of 6.392 life years and additional expenditure of 14 833 pounds. If decision makers are prepared to pay up to 10 000 pounds an additional life year, this would imply a net benefit of 49 090 pounds (range 12 300 pounds- 59 000 pounds), which would be available to detect each additional infected woman in an antenatal screening programme. In London, universal antenatal screening would be cost effective compared with a selective screening under any reasonable assumptions about screening costs. Outside London, universal screening with uptake above 90% would be cost effective with a 0.60 pounds HIV antibody test cost and up to 3.5 minutes for pretest discussion. Cost effectiveness of universal testing is lower if selective testing can achieve high uptake among those at higher risk. A universal strategy with only 50% uptake may not be less cost effective in low prevalence districts and may cost more and be less effective than a well run selective strategy. CONCLUSIONS: Universal screening with pretest discussion should be adopted throughout the United Kingdom as part of routine antenatal care as long as test costs can be kept low and uptake high.

Anti-HIV Agents↗

PubMed1999

Development of a disease specific questionnaire to measure health related quality of life in patients with chronic liver disease.

BACKGROUND AND AIMS: To develop and assess a disease specific instrument for measuring health related quality of life (HRQL) in patients with chronic liver disease (CLD). METHODS: Based on responses from 60 patients with chronic liver disease, from 20 liver experts, and from a Medline search of the literature, items potentially affecting the HRQL of these patients were identified. A separate sample of 75 patients identified which items they found problematic and rated their importance. Results were explored using factor analysis; domains were chosen and items placed within domains. Redundant questions were eliminated and the final questionnaire was pretested in 10 patients. Using this instrument, HRQL was assessed in a further 133 patients with various types and stages of liver disease. RESULTS: Patients, experts, and the literature search identified 156 items of potential importance. Of these, 35 proved important to over 50% of 75 respondents in the item reduction sample. The factor analysis suggested six domains. After eliminating redundancies, the Chronic Liver Disease Questionnaire (CLDQ) included 29 items in the following domains: fatigue, activity, emotional function, abdominal symptoms, systemic symptoms, and worry. In pretesting, patients found the CLDQ clear and easy to complete in 10 minutes. In another 133 patients, the CLDQ showed a gradient between patients without cirrhosis, Child's A cirrhosis, and those with Child's B or C cirrhosis. CLDQ has evidence for moderate reliability at six months and seems to be responsive. CONCLUSION: The CLDQ is short, easy to administer, produces both a summary score and domain scores, and correlates with the severity of liver disease.

Analysis of Variance↗

PubMed1994

Direct access exercise electrocardiography: a new service that improves the management of suspected ischaemic heart disease in the community.

OBJECTIVE: To assess the safety and value of an exercise electrocardiography service for the diagnosis of suspected ischaemic heart disease to which general practitioners have direct access. DESIGN: Direct access to a hospital exercise electrocardiography service was offered on a trial basis to 122 general practitioners in a defined urban area. Maximal exercise tests were performed according to the modified Bruce protocol and the results were dispatched promptly to the referring doctors who were responsible for the subsequent management of their patients. SETTING: All general practices in north and west Belfast (combined list size about 180,000) and the regional medical cardiology centre. PATIENTS: 212 request forms were received in a two year period and 192 eligible patients attended for exercise testing. All patients were suspected to have pain due to myocardial ischaemia, were aged < or = 65, and had no contraindications to exercise testing. MAIN OUTCOME MEASURES: Proportion of general practitioners who used the service. Proportion of exercise tests that were positive. Referring doctors' assessment of the service. RESULTS: 43% of general practitioners referred patients and 34 tests (18%) were positive. No complications occurred. The pretest likelihood of ischaemic heart disease, assessed by the referring doctor, was high in 48 (25%), moderate in 82 (43%), and low in 62 (32%). A high pretest likelihood of ischaemic heart disease predicted a positive test result with a sensitivity of 50% and specificity of 80%. General practitioners decided to refer 19 (10%) patients to a hospital cardiology department for further assessment, including 16 of the 34 who had a positive exercise test. In most cases the service was found to be helpful and 97% of patients would have been referred directly to a hospital cardiology clinic if it had not been available. CONCLUSIONS: Direct access exercise electrocardiography for patients with suspected ischaemic heart disease is safe, feasible, and helpful to general practitioners. This service seems to reduce the number of patients referred to cardiology outpatient clinics and to facilitate the management of these patients in the community.

Cardiology Service, Hospital↗

PubMed1996

Prediction of psychological functioning one year after the predictive test for Huntington's disease and impact of the test result on reproductive decision making.

For people at risk for Huntington's disease, the anxiety and uncertainty about the future may be very burdensome and may be an obstacle to personal decision making about important life issues, for example, procreation. For some at risk persons, this situation is the reason for requesting predictive DNA testing. The aim of this paper is two-fold. First, we want to evaluate whether knowing one's carrier status reduces anxiety and uncertainty and whether it facilitates decision making about procreation. Second, we endeavour to identify pretest predictors of psychological adaptation one year after the predictive test (psychometric evaluation of general anxiety, depression level, and ego strength). The impact of the predictive test result was assessed in 53 subjects tested, using pre- and post-test psychometric measurement and self-report data of follow up interviews. Mean anxiety and depression levels were significantly decreased one year after a good test result; there was no significant change in the case of a bad test result. The mean personality profile, including ego strength, remained unchanged one year after the test. The study further shows that the test result had a definite impact on reproductive decision making. Stepwise multiple regression analyses were used to select the best predictors of the subject's post-test reactions. The results indicate that a careful evaluation of pretest ego strength, depression level, and coping strategies may be helpful in predicting post-test reactions, independently of the carrier status. Test result (carrier/ non-carrier), gender, and age did not significantly contribute to the prediction. About one third of the variance of post-test anxiety and depression level and more than half of the variance of ego strength was explained, implying that other psychological or social aspects should also be taken into account when predicting individual post-test reactions.

Adult↗

PubMed1986

Quantitative assessment of the value of spirometry.

To determine the value of simple spirometric measurements in the diagnostic assessment of breathless patients, doctors requesting such tests were asked to predict the likely ventilatory abnormality, expressing these pretest predictions as probabilities. Comparison of these pretest predictions with the test results allowed an analysis of the doctors' ability to identify lung function abnormalities and an assessment of the diagnostic usefulness of the test. Predictions and spirometric measurements were made in 123 patients. Doctors expressed preference for a particular spirometric category in 112 cases, of which 13 were predicted to have a restrictive defect, 77 were predicted to have an obstructive defect, and 22 were predicted to be normal. Spirometry showed that nine patients had a restrictive defect, 79 had an obstructive defect, and 24 had normal indices. The study showed that 61% of the tests gave a result that doctors predicted as being unlikely. The study also showed that doctors had difficulty in identifying the reversibility of airflow obstruction in patients in whom they correctly predicted obstruction. Spirometry fulfils a useful role in the diagnosis of breathless patients.

Adolescent↗

PubMed2007

Role of functional MR in determining language dominance in epilepsy and nonepilepsy populations: a Bayesian analysis.

PURPOSE: To determine the role of functional magnetic resonance (MR) imaging in assessing hemispheric language dominance in epilepsy and nonepilepsy populations. MATERIALS AND METHODS: A Bayesian analysis study was performed. The study was based on data from the published literature; thus, institutional review board approval was not required. The literature was reviewed to obtain pretest probabilities and likelihood ratios, which were analyzed to determine the posttest probability of language dominance by using functional MR imaging. Pretest probabilities of different hand dominances in epilepsy and nonepilepsy populations were obtained from the largest studies available in the literature. Likelihood ratios were derived from the sensitivity and specificity of functional MR imaging by using electrocortical stimulation (ECS) and the Wada test as reference standards. RESULTS: Likelihood ratios for functional MR in determining language dominance were 9.3 and 12.3 with ECS and the Wada test as reference standards, respectively. Use of functional MR increased the final posttest probabilities of hemispheric language dominance in epilepsy and nonepilepsy populations. In the nonepilepsy population, regardless of hand dominance, there was very high posttest probability (>or=96%) of a correlation between functional MR hemisphere activation and definite left-hemisphere language dominance. In the epilepsy population with right-hand dominance or ambidexterity, there was very high posttest probability (>or=95%) of a correlation between functional MR hemisphere activation and definite left-hemisphere language dominance. In the left-handed nonepileptic subjects, there was high posttest probability (81%-83%) of a correlation between functional MR hemisphere activation and definite right-hemisphere language dominance. In the left-handed epilepsy population, there was high posttest probability (80%-97%) of a correlation between functional MR hemisphere activation and definite left-hemisphere language dominance. In the epilepsy population with ambidexterity, there was high posttest probability (80%-87%) of correlations between functional MR hemisphere activation and both definite right-hemisphere and bilateral language dominance. CONCLUSION: Use of functional MR increases importantly the posttest probabilities of hemispheric language dominance in multiple subgroups of individuals with and without epilepsy.

Bayes Theorem↗

PubMed2002

The effectiveness of web-based, multimedia tutorials for teaching methods of human body composition analysis.

This study examined the effectiveness of a series of Web-based, multimedia tutorials on methods of human body composition analysis. Tutorials were developed around four body composition topics: hydrodensitometry (underwater weighing), dual-energy X-ray absorptiometry, bioelectrical impedance analysis, and total body electrical conductivity. Thirty-two students enrolled in the course were randomly assigned to learn the material through either the Web-based tutorials only ("Computer"), a traditional lecture format ("Lecture"), or lectures supplemented with Web-based tutorials ("Both"). All students were administered a validated pretest before randomization and an identical posttest at the completion of the course. The reliability of the test was 0.84. The mean score changes from pretest to posttest were not significantly different among the groups (65.4 plus minus 17.31, 78.82 plus minus 21.50, and 76 plus minus 21.22 for the Computer, Both, and Lecture groups, respectively). Additionally, a Likert-type assessment found equally positive attitudes toward all three formats. The results indicate that Web-based tutorials are as effective as the traditional lecture format for teaching these topics.

Body Composition↗

PubMed2000

Comparison of naive and experienced students of elementary physiology on performance in an advanced course.

The purpose of this study was to determine whether, in comparison with naive students, experienced students who have completed an elementary physiology course 1) have a greater knowledge level of physiology and 2) perform better in an upper division physiology course. The educational setting for this study was the cardiovascular block of an advanced undergraduate level course entitled Principles of Human Physiology (PGY 412). The study employed students who had completed elementary physiology (PGY 206) at the University of Kentucky (group 1), students who had completed elementary physiology in another academic program (group 2), and naive students with no prior physiology experience (group 3). A cardiovascular pretest was presented during the opening session of the cardiovascular block in PGY 412. Respective scores for the three groups were 29.4%, 31.7%, and 24.1%, and there were no significant between-group differences. Respective scores on the same pretest items given as a posttest at the end of the cardiovascular block were 90.4%, 91.4%, and 90.4%, and, again, there were no significant between-group differences. Respective scores on other cardiovascular test items given at the end of the block were 78.9%, 78.7%, and 81.1%. Interestingly, the highest score here was achieved by the naive students (group 3), but, once again, between-group differences were not significant. In summary, on the basis of pretest/posttest examination of cardiovascular physiology between naive and experienced students, the results of this study indicate 1) that the common assumption that students entering advanced level physiology courses have a significant retention of knowledge from elementary physiology is not valid and 2) that completion of an elementary physiology course does not offer an advantage in learning advanced material.

Cardiovascular Physiological Phenomena↗