Racial differences in triage assessment at rural vs urban Maine emergency departments

Data continue to accumulate demonstrating that those belonging to racialized groups face implicit bias in the emergency care delivery system across many indices, including triage assessment. The Emergency Severity Index (ESI) was developed and widely implemented across the US to improve the objectivity of triage assessment and prioritization of care delivery; however, research continues to support the presence of subjective bias in triage assessment. We sought to assess the relationship between perceived race and/or need for translator and assigned ESI score and whether this was impacted by hospital geography. We performed retrospective EMR-based review of patients presenting to urban and rural emergency departments of a health system in Maine with one of the top ten most common chief complaints (CC) across a 5-year period, excluding psychiatric CCs. We used multivariable regression to analyze the relationships between perceived race, need for translator, and gender with ESI score, wait time, and hallway bed assignments. We found that patients perceived as non-white were more likely to receive lower acuity ESI scores and have longer wait times as compared to patients perceived as white. Patients perceived as female were more likely to receive lower acuity scores and wait longer to be seen than patients perceived as male. The need for an interpreter was associated with increased wait times but not significantly associated with ESI score. After stratification by hospital geography, evidence of subjective bias was limited to urban emergency departments and was not evident in rural emergency departments. Further investigation of subjective bias in emergency departments in Maine, particularly in urban settings, is warranted.

A pilot study evaluating the use of sirolimus in children and young adults with desmoid-type fibromatosis

Deregulation of the mTOR pathway may play an important role in tumor biology when the APC/β-catenin pathway is disrupted in desmoid-type fibromatosis (DT). A pilot study was conducted to determine whether sirolimus can block the mTOR pathway (primary aim) as well as determine whether it can safely be given in the preoperative setting, decrease tumor size/recurrence, and decrease tumor-associated pain in children and young adults (secondary aims) with DT. Nine subjects ages 5-28 years were enrolled from 2014 to 2017 across four centers. Sirolimus was feasible and was associated with a nonstatistically significant decrease in pS706K activation.

Telemedicine Improves Rate of Successful First Visit to NICU Follow-up Clinic

OBJECTIVES

NICU graduates require ongoing surveillance in follow-up clinics because of the risk of lower cognitive, motor, and academic performance. We hypothesized that multiple programmatic changes, including availability of telemedicine consultation before hospital discharge, would improve NICU follow-up clinic attendance rates.

METHODS

In this retrospective study, we included infants who survived and were premature (≤29 6/7 weeks/<1500 g) or had brain injury (grade III/IV intraventricular hemorrhage, stroke or seizure, hypoxic ischemic encephalopathy). We compared rates of follow-up for the early cohort (January 2018-June 2019; no telemedicine) with the late cohort (May 2020-May 2021; telemedicine available); and performed a mediation analysis to assess other programmatic changes for the late cohort including improved documentation to parents and primary care provider regarding NICU follow-up.

RESULTS

The rate of successful 12-month follow-up improved from 26% (early cohort) to 61% (late cohort) (P < .001). After controlling for maternal insurance, the odds of attending a 12-month follow-up visit were 3.7 times higher for infants in the late cohort, for whom telemedicine was available (confidence interval, 1.8-7.9). Approximately 37% of this effect was mediated by including information for NICU follow-up in the discharge documentation for parents (P < .001).

CONCLUSIONS

Telemedicine consultation before NICU discharge, in addition to improving communication regarding the timing and importance of NICU follow-up, was effective at improving the rate of attendance to NICU follow-up clinics.

Simulation-Based Outreach Program Improves Rural Hospitals’ Team Confidence in Neonatal Resuscitation

Introduction: Neonatal resuscitation is a high acuity, low occurrence event (HALO), and in rural community hospitals, low birth rates prevent providers from regular opportunities to maintain essential resuscitation skills. Simulation is an effective training modality for medical education, although resources for simulation are often limited in rural hospitals. Our primary objective was to test the hypothesis that in situ neonatal resuscitation simulation training improves rural hospitals' delivery room team confidence in performing key Neonatal Resuscitation Program^® (NRP^®) skills. Our secondary objective was to compare confidence to performance as measured by adherence to NRP® guidelines.

Methods: We conducted a quasi-experimental pre-training survey and post-training survey of delivery room team confidence in NRP^® skills at five level one delivery hospitals before and after an in situ simulation training program. Participants included rural hospitals’ usual delivery room team members. Participants rated their confidence on a five-point Likert scale. Simulations were analyzed using an adapted version of a validated scoring tool for NRP^® adherence and presented as overall percentage scores.

Results: Our data demonstrate a significant improvement in self-assessed confidence levels pre- and post-simulation training in key areas of neonatal resuscitation. Participants reported higher confidence in airway management (4 vs. 3, p=0.003), emergency intravenous access (3 vs. 2, p=0.007), and the ability to manage a code in the delivery room (4 vs. 3, p=0.013) and the operating room (4 vs. 3, p=0.028). Improvements were also noted in their team member’s knowledge and skills to perform neonatal resuscitation. While improvements were appreciated in confidence, the performance of skills (NRP^® adherence scores) was often in the sub-optimal performance range.

Conclusions: An in situ-based neonatal resuscitation outreach simulation program improves self-confidence among rural delivery room teams. Additional research is needed to understand how to translate improved confidence into actual improved performance. 

Comparing whole-genome shotgun sequencing and DNA metabarcoding approaches for species identification and quantification of pollen species mixtures

Molecular identification of mixed-species pollen samples has a range of applications in various fields of research. To date, such molecular identification has primarily been carried out via amplicon sequencing, but whole-genome shotgun (WGS) sequencing of pollen DNA has potential advantages, including (1) more genetic information per sample and (2) the potential for better quantitative matching. In this study, we tested the performance of WGS sequencing methodology and publicly available reference sequences in identifying species and quantifying their relative abundance in pollen mock communities. Using mock communities previously analyzed with DNA metabarcoding, we sequenced approximately 200Mbp for each sample using Illumina HiSeq and MiSeq. Taxonomic identifications were based on the Kraken k-mer identification method with reference libraries constructed from full-genome and short read archive data from the NCBI database. We found WGS to be a reliable method for taxonomic identification of pollen with near 100% identification of species in mixtures but generating higher rates of false positives (reads not identified to the correct taxon at the required taxonomic level) relative to rbcL and ITS2 amplicon sequencing. For quantification of relative species abundance, WGS data provided a stronger correlation between pollen grain proportion and sequence read proportion, but diverged more from a 1:1 relationship, likely due to the higher rate of false positives. Currently, a limitation of WGS-based pollen identification is the lack of representation of plant diversity in publicly available genome databases. As databases improve and costs drop, we expect that eventually genomics methods will become the methods of choice for species identification and quantification of mixed-species pollen samples.

Complication Rates and Short-Term Outcomes After Operative Hammertoe Correction in Older Patients

BACKGROUND

Hammertoe deformities are the most common lesser toe deformity. To date, no studies have looked at outcomes of operative management in the geriatric population, which may be at greater risk for complications or functional compromise because of comorbidities.

METHODS

Data on 58 patients undergoing operative correction of hammertoe deformities were prospectively collected. Clinical outcomes were assessed using preoperative and postoperative visual analogue scale (VAS) and Short Form Health Survey (SF-36) scores with a minimum of 6-month follow-up. Patients were divided into 2 groups on the basis of age at the time of surgery: younger than 65 and 65 and older. Complication rates and mean VAS and SF-36 improvement were compared. Forty-seven patients met inclusion criteria (7 men, 40 women), with 26 patients (37 toes) in the younger cohort and 21 patients (39 toes) in the older cohort.

RESULTS

Overall, patients demonstrated significant improvement from baseline to 6 and 12 months postoperatively in VAS ( P < .001 and P < .001) and SF-36 ( P < .001 and P < .001) scores. Mean improvement in VAS and SF-36 scores was not significantly different between the groups at 6 and 12 months postoperatively. Complications occurred in 13.5% and 10.3% of patients in the younger and older cohorts, respectively.

CONCLUSIONS

Outcomes of operative correction of hammertoe deformities in older patients were similar to outcomes in younger patients after greater than 6 months of follow-up. Overall improvement in VAS and SF-36 was statistically significant for both cohorts. There was no associated increase in complications for older patients.

LEVEL OF EVIDENCE

Level, III comparative series.

Decreasing prevalence combined with increasing eradication of Helicobacter pylori infection in the United States has not resulted in fewer hospital admissions for peptic ulcer disease-related complications

BACKGROUND

Helicobacter pylori infection is a major cause of peptic ulcer disease, but the prevalence of this infection has been decreasing steadily. Additionally, eradication of H. pylori decreases ulcer recurrence and prevents ulcer complications such as bleeding.

AIM

To examine whether the decreased prevalence of H. pylori and increased use of eradication regimens have affected the prevalence of peptic ulcer disease-related hospitalizations.

METHODS

We chose to study a period between 1996 and 2005. The number of gastric and duodenal ulcers as primary or secondary hospital discharge diagnoses per year for the 10-year span was collected from five large US hospitals. Collected data were analysed using Spearman correlation.

RESULTS

No statistically significant trend was observed in the number of gastric or duodenal ulcers listed as primary or secondary discharge diagnoses at any of the five healthcare centres.

CONCLUSIONS

Despite a decreasing prevalence of H. pylori and the increasing use of successful H. pylori eradication regimens, the prevalence of peptic ulcer disease and its complications has not changed. In the US other aetiologies, including non-steroidal anti-inflammatory drugs, may be playing a larger role than once thought.

Voornaam is not (really) a homophone: Lexical prosody and lexical access in Dutch

Four experiments examined Dutch listeners' use of suprasegmental information in spoken-word recognition. Isolated syllables excised from minimal stress pairs such as VOORnaam/voorNAAM could be reliably assigned to their source words. In lexical decision, no priming was observed from one member of minimal stress pairs to the other, suggesting that the pairs' segmental ambiguity was removed by suprasegmental information. Words embedded in nonsense strings were harder to detect if the nonsense string itself formed the beginning of a competing word, but a suprasegmental mismatch to the competing word significantly reduced this inhibition. The same nonsense strings facilitated recognition of the longer words of which they constituted the beginning, but again the facilitation was significantly reduced by suprasegmental mismatch. Together these results indicate that Dutch listeners effectively exploit suprasegmental cues in recognizing spoken words. Nonetheless, suprasegmental mismatch appears to be somewhat less effective in constraining activation than segmental mismatch.

Cross-language word segmentation by 9-month-olds

Dutch-learning and English-learning 9-month-olds were tested, using the Headturn Preference Procedure, for their ability to segment Dutch words with strong/weak stress patterns from fluent Dutch speech. This prosodic pattern is highly typical for words of both languages. The infants were familiarized with pairs of words and then tested on four passages, two that included the familiarized words and two that did not. Both the Dutch- and the English-learning infants gave evidence of segmenting the targets from the passages, to an equivalent degree. Thus, English-learning infants are able to extract words from fluent speech in a language that is phonetically different from English. We discuss the possibility that this cross-language segmentation ability is aided by the similarity of the typical rhythmic structure of Dutch and English words.

Constraints of vowels and consonants on lexical selection: cross-linguistic comparisons

Languages differ in the constitution of their phonemic repertoire and in the relative distinctiveness of phonemes within the repertoire. In the present study, we asked whether such differences constrain spoken-word recognition, via two word reconstruction experiments, in which listeners turned non-words into real words by changing single sounds. The experiments were carried out in Dutch (which has a relatively balanced vowel-consonant ratio and many similar vowels) and in Spanish (which has many more consonants than vowels and high distinctiveness among the vowels). Both Dutch and Spanish listeners responded significantly faster and more accurately when required to change vowels as opposed to consonants; when allowed to change any phoneme, they more often altered vowels than consonants. Vowel information thus appears to constrain lexical selection less tightly (allow more potential candidates) than does consonant information, independent of language-specific phoneme repertoire and of relative distinctiveness of vowels.

Merging information in speech recognition: feedback is never necessary

Top-down feedback does not benefit speech recognition; on the contrary, it can hinder it. No experimental data imply that feedback loops are required for speech recognition. Feedback is accordingly unnecessary and spoken word recognition is modular. To defend this thesis, we analyse lexical involvement in phonemic decision making. TRACE (McClelland & Elman 1986), a model with feedback from the lexicon to prelexical processes, is unable to account for all the available data on phonemic decision making. The modular Race model (Cutler & Norris 1979) is likewise challenged by some recent results, however. We therefore present a new modular model of phonemic decision making, the Merge model. In Merge, information flows from prelexical processes to the lexicon without feedback. Because phonemic decisions are based on the merging of prelexical and lexical information, Merge correctly predicts lexical involvement in phonemic decisions in both words and nonwords. Computer simulations show how Merge is able to account for the data through a process of competition between lexical hypotheses. We discuss the issue of feedback in other areas of language processing and conclude that modular models are particularly well suited to the problems and constraints of speech recognition.

Seroprevalence of Helicobacter pylori infection in cystic fibrosis and its cross-reactivity with anti-pseudomonas antibodies

BACKGROUND

The prevalence of Helicobacter pylori infection and its role in gastroduodenal disease in cystic fibrosis (CF) are controversial. Additionally, serologic determination of infection in this population may be inaccurate because of cross-reactivity with other bacterial species. The seroprevalence of H. pylori in a cohort of patients with CF and its cross-reactivity with Pseudomonas antibodies were investigated.

METHODS

A research enzyme-linked immunosorbent assay (ELISA), and three commercial serologic assays (PyloriStat; BioWhittaker, Walkersville, MD, U.S.A.; Flexsure; SmithKline Diagnostics, Inc., San Jose, CA, U.S.A.; and HM-CAP; EPI, Stony Brook, NY, U.S.A.) at three independent laboratories determined the seroprevalence of anti-H. pylori IgG antibodies in 70 patients with CF. Cross-reactivity between solid-phase H. pylori antigens and Pseudomonas antibodies was ascertained by a competitive inhibition assay, preadsorbing sera of patients with CF with whole cell proteins from different Pseudomonas species, and serum reanalysis by each assay. Western blot analysis before and after adsorption was performed to identify potential cross-reactive antigens.

RESULTS

The research ELISA, Flexsure, Pyloristat, and HM-CAP initially showed H. pylori seropositivity of 47%, 28%, 24%, and 37%, respectively. Postadsorption seropositivity declined to 8%, 0%, 0%, and 15%, respectively. All patients with research ELISA true-positive results were confirmed endoscopically to have H. pylori infection. Western blot analysis showed a 31-kDa H. pylori protein with antigenic epitopes common to both bacterial species.

CONCLUSIONS

Cross-reactivity between solid-phase H. pylori antigens and anti-Pseudomonas antibodies occurs in patients with CF. A high index of suspicion should be assumed in evaluating results of serologic H. pylori tests in this population. Preadsorption of CF sera with Pseudomonas proteins should be used in serologic testing.

Effects of dehydroepiandrosterone vs androstenedione supplementation in men

PURPOSE

The purpose of this study was to compare the effects of short-term (12 wk) supplementation with androstenedione versus dehydroepiandrosterone (DHEA) on body composition, strength, and related hormones in middle-aged men.

METHODS

A randomized, placebo-controlled, double-blind design was used to study 40 healthy, trained (>1 yr weight training) male subjects (mean +/- SD: age 48.1 +/- 3.9 yr; weight 79.8 +/- 9.8 kg). Subjects were randomly assigned to one of three groups: placebo (P), DHEA (D), or androstenedione (A). Supplements (50 mg capsules) were ingested two times daily for 12 wk. All testing, including venous blood samples, body composition, and performance, was conducted at three time points: presupplementation (1 d), at 6 wk, and postsupplementation (12 wk).

RESULTS

Despite a small increase in lean body mass (0.8 +/- 0.4 and 0.5 +/- 0.3 kg) and mean strength (6.8 +/- 2.7 and 5.7 +/- 2.4 kg) in both D and A groups respectively, these changes were not significantly different from P. In D, there was a significantly greater increase in DHEA-S levels than in P (P < 0.05). There were no adverse side effects demonstrated during D or A supplementation including significant changes in PSA, liver function, or lipid levels (P < 0.05).

CONCLUSIONS

The results of this study suggest that supplementation with 100 mg x d(-1) of either androstenedione or DHEA does not independently elicit a statistically significant increase in lean body mass, strength, or testosterone levels in healthy adult men over a 12-wk period.

Ten-day triple therapy with ranitidine bismuth citrate, amoxicillin, and clarithromycin in eradicating Helicobacter pylori

OBJECTIVE

Fourteen-day therapy with ranitidine bismuth citrate, amoxicillin, and clarithromycin has been shown to have a high Helicobacter pylori eradication rate (> 90%) in U.S. trials. The aim of this study was to determine the H. pylori eradication rate of a ranitidine bismuth citrate-based triple regimen of shorter duration (10 days), which has been shown to be effective in Europe.

METHODS

Dyspeptic patients who had a positive baseline 13C-urea breath test and either a positive antral rapid urease test or positive IgG serology were studied. Treatment consisted of ranitidine bismuth citrate 400 mg, clarithromycin 500 mg, and amoxicillin 1 g, all given b.i.d. for 10 days. Eradication was determined >4 wk after completion of therapy by the 13C-urea breath test (enrichment <2.4%). Results are expressed for intent-to-treat (all patients randomized even if they did not take the drug) and per-protocol (major protocol violators excluded) analyses.

RESULTS

Seventy-seven patients with a mean age of 48 +/- 1.8 yr were studied. Forty-eight patients had eradication of H. pylori with this regimen (62%), 16 patients (21%) did not have eradication, and 13 patients (17%) did not return for breath testing. By intent-to-treat analysis the eradication rate was 62% (95% confidence intervals [CI], 51%, 73%) and by per-protocol analysis the eradication rate was 75% (95% CI, 63%, 85%).

CONCLUSIONS

Ten-day, twice-daily therapy with ranitidine bismuth citrate, amoxicillin, and clarithromycin has an eradication rate that ranges from 62-75%. Fourteen-day therapy may be preferable because of higher eradication rates.

Pitch accent in spoken-word recognition in Japanese

Three experiments addressed the question of whether pitch-accent information may be exploited in the process of recognizing spoken words in Tokyo Japanese. In a two-choice classification task, listeners judged from which of two words, differing in accentual structure, isolated syllables had been extracted (e.g., ka from baka HL or gaka LH); most judgments were correct, and listeners' decisions were correlated with the fundamental frequency characteristics of the syllables. In a gating experiment, listeners heard initial fragments of words and guessed what the words were; their guesses overwhelmingly had the same initial accent structure as the gated word even when only the beginning CV of the stimulus (e.g., na- from nagasa HLL or nagashi LHH) was presented. In addition, listeners were more confident in guesses with the same initial accent structure as the stimulus than in guesses with different accent. In a lexical decision experiment, responses to spoken words (e.g., ame HL) were speeded by previous presentation of the same word (e.g., ame HL) but not by previous presentation of a word differing only in accent (e.g., ame LH). Together these findings provide strong evidence that accentual information constrains the activation and selection of candidates for spoken-word recognition.

Optimal treatment for duodenal ulcer disease: a cost-decision analysis in Malaysian patients

The aim of the present study was to determine the cost-efficiency of different duodenal ulcer disease treatment practices in Malaysia. Six Malaysian gastroenterologists met to discuss the direct costs related to Helicobacter pylori (HP) eradication treatment. Five treatment strategies were compared: (i) histamine H2 receptor antagonists (H2RA), acid suppression therapy for 6 weeks followed by maintenance therapy as needed; (ii) bismuth triple + proton pump inhibitor (PPI), bismuth (120 mg, q.i.d.), metronidazole (400 mg; t.i.d.), tetracycline (500 mg, q.i.d.) for 7 days and PPI, b.i.d., for 7 days; (iii) OAC, omeprazole (20 mg, b.i.d.), amoxycillin (1000 mg, b.i.d.) and clarithromycin (500 mg, b.i.d.) for 7 days; (iv) OMC, omeprazole (20mg, b.i.d.), metronidazole (400mg, b.i.d.) and clarithromycin (500 mg, b.i.d.) for 7 days; and (v) OAM, omeprazole (20 mg, b.i.d.), amoxycillin (1000 mg, b.i.d.) and metronidazole (400 mg, b.i.d.) for 7 days. A decision tree model was created to determine which therapy would be the most cost-effective. The model considered eradication rates, resistance to anti-microbial agents, compliance and cost implications of treatment regimens, physician visits and ulcer recurrences during a 1 year time period assumption. The H2RA maintenance therapy was the most expensive treatment at Malaysian Ringgit (MR) 2335, followed by bismuth triple therapy (MR 1839), OMC (MR 1786), OAM (MR 1775) and OAC, being the most cost-effective therapy, at MR 1679. In conclusion, HP eradication therapy is superior to H2RA maintenance therapy in the treatment of duodenal ulcer disease. Of the HP eradication regimens, OAC is the most cost-effective.

Effects of phoneme repertoire on phoneme decision

In three experiments, listeners detected vowel or consonant targets in lists of CV syllables constructed from five vowels and five consonants. Responses were faster in a predictable context (e.g., listening for a vowel target in a list of syllables all beginning with the same consonant) than in an unpredictable context (e.g., listening for a vowel target in a list of syllables beginning with different consonants). In Experiment 1, the listeners' native language was Dutch, in which vowel and consonant repertoires are similar in size. The difference between predictable and unpredictable contexts was comparable for vowel and consonant targets. In Experiments 2 and 3, the listeners' native language was Spanish, which has four times as many consonants as vowels; here effects of an unpredictable consonant context on vowel detection were significantly greater than effects of an unpredictable vowel context on consonant detection. This finding suggests that listeners' processing of phonemes takes into account the constitution of their language's phonemic repertoire and the implications that this has for contextual variability.

Use caution with serologic testing for Helicobacter pylori infection in children

Commercial serologic assays accurately detect adult Helicobacter pylori infection. Their use in children remains controversial. An ELISA to detect H. pylori IgG in children was developed and compared with three commercial assays. ELISA standardization was done with sera from all ages and validation was done with another cohort of sera with known H. pylori status. Three commercial serologic assays were subsequently compared against this pediatric ELISA at independent sites, at which 142 pediatric serum samples from different countries were evaluated. The pediatric ELISA was 91.4% sensitive. Assay 3 demonstrated a sensitivity of 78%. Less sensitivity was observed for assay 1 (70%) and assay 2 (63%). Accuracy of commercial assays was greatly reduced when sera from developing countries and younger ages were evaluated. Results of serologic tests used to diagnose H. pylori should be interpreted with caution when evaluating children with abdominal pain. Accurate serologic assays in children may be more important for epidemiologic research than for clinical decision making.

The possible-word constraint in the segmentation of continuous speech

We propose that word recognition in continuous speech is subject to constraints on what may constitute a viable word of the language. This Possible-Word Constraint (PWC) reduces activation of candidate words if their recognition would imply word status for adjacent input which could not be a word--for instance, a single consonant. In two word-spotting experiments, listeners found it much harder to detect apple, for example, in fapple (where [f] alone would be an impossible word), than in vuffapple (where vuff could be a word of English). We demonstrate that the PWC can readily be implemented in a competition-based model of continuous speech recognition, as a constraint on the process of competition between candidate words; where a stretch of speech between a candidate word and a (known or likely) word boundary is not a possible word, activation of the candidate word is reduced. This implementation accurately simulates both the present results and data from a range of earlier studies of speech segmentation.

Prosody in the comprehension of spoken language: a literature review

Research on the exploitation of prosodic information in the comprehension of spoken language is reviewed. The research falls into three main areas: the use of prosody in the recognition of spoken words, in which most attention has been paid to the question of whether the prosodic structure of a word plays a role in initial activation of stored lexical representations; the use of prosody in the computation of syntactic structure, in which the resolution of global and local ambiguities has formed the central focus; and the role of prosody in the processing of discourse structure, in which there has been a preponderance of work on the contribution of accentuation and deaccentuation to integration of concepts with an existing discourse model. The review reveals that in each area progress has been made towards new conceptions of prosody's role in processing, and in particular this has involved abandonment of previously held deterministic views of the relationship between prosodic structure and other aspects of linguistic structure.

Lexical tone in Cantonese spoken-word processing

In three experiments, the processing of lexical tone in Cantonese was examined. Cantonese listeners more often accepted a nonword as a word when the only difference between the nonword and the word was in tone, especially when the F0 onset difference between correct and erroneous tone was small. Same-different judgments by these listeners were also slower and less accurate when the only difference between two syllables was in tone, and this was true whether the F0 onset difference between the two tones was large or small. Listeners with no knowledge of Cantonese produced essentially the same same-different judgment pattern as that produced by the native listeners, suggesting that the results display the effects of simple perceptual processing rather than of linguistic knowledge. It is argued that the processing of lexical tone distinctions may be slowed, relative to the processing of segmental distinctions, and that, in speeded-response tasks, tone is thus more likely to be misprocessed than is segmental structure.

The representation of Japanese moraic nasals

Nasal consonants in syllabic coda position in Japanese assimilate to the place of articulation of a following consonant. The resulting forms may be perceived as different realizations of a single underlying unit, and indeed the kana orthographies represent them with a single character. In the present study, Japanese listeners' response time to detect nasal consonants was measured. Nasals in coda position, i.e., moraic nasals, were detected faster and more accurately than nonmoraic nasals, as reported in previous studies. The place of articulation with which moraic nasals were realized affected neither response time nor accuracy. Non-native subjects who knew no Japanese, given the same materials with the same instructions, simply failed to respond to moraic nasals which were realized bilabially. When the nasals were cross-spliced across place of articulation contexts the Japanese listeners still showed no significant place of articulation effects, although responses were faster and more accurate to unspliced than to cross-spliced nasals. When asked to detect the phoneme following the (cross-spliced) moraic nasal, Japanese listeners showed effects of mismatch between nasal and context, but non-native listeners did not. Together, these results suggest that Japanese listeners are capable of very rapid abstraction from phonetic realization to a unitary representation of moraic nasals; but they can also use the phonetic realization of a moraic nasal effectively to obtain anticipatory information about following phonemes.

Speeded detection of vowels: a cross-linguistic study

In four experiments, listeners' response times to detect vowel targets in spoken input were measured. The first three experiments were conducted in English. In two, one using real words and the other, nonwords, detection accuracy was low, targets in initial syllables were detected more slowly than targets in final syllables, and both response time and missed-response rate were inversely correlated with vowel duration. In a third experiment, the speech context for some subjects included all English vowels, while for others, only five relatively distinct vowels occurred. This manipulation had essentially no effect, and the same response pattern was again observed. A fourth experiment, conducted in Spanish, replicated the results in the first three experiments, except that miss rate was here unrelated to vowel duration. We propose that listeners' responses to vowel targets in naturally spoken input are effectively cautious, reflecting realistic appreciation of vowel variability in natural context.

Interaction with autonomy: multiple output models and the inadequacy of the Great Divide

There are currently a number of psycholinguistic models in which processing at a particular level of representation is characterized by the generation of multiple outputs, with resolution--but not generation--involving the use of information from higher levels of processing. Surprisingly, models with this architecture have been characterized as autonomous within the domain of word recognition but as interactive within the domain of sentence processing. We suggest that the apparent confusion is not, as might be assumed, due to fundamental differences between lexical and syntactic processing. Rather, we believe that the labels in each domain were chosen in order to obtain maximal contrast between a new model and the model or models that were currently dominating the field. The contradiction serves to highlight the inadequacy of a simple autonomy/interaction dichotomy for characterizing the architectures of current processing models.

Competition and segmentation in spoken-word recognition

Spoken utterances contain few reliable cues to word boundaries, but listeners nonetheless experience little difficulty identifying words in continuous speech. The authors present data and simulations that suggest that this ability is best accounted for by a model of spoken-word recognition combining competition between alternative lexical candidates, and sensitivity to prosodic structure. In a word-spotting experiment, stress pattern effects emerged most clearly when there were many competing lexical candidates for part of the input. Thus, competition between simultaneously active word candidates can modulate the size of prosodic effects, which suggests that spoken-word recognition must be sensitive both to prosodic structure and to the effects of competition. A version of the Shortlist model (D. G. Norris, 1994b) incorporating the Metrical Segmentation Strategy (A. Cutler & D. Norris, 1988) accurately simulates the results using a lexicon of more than 25,000 words.

The strong/weak syllable distinction in English

Strong and weak syllables in English can be distinguished on the basis of vowel quality, of stress, or of both factors. Critical for deciding between these factors are syllables containing unstressed unreduced vowels, such as the first syllable of automata. In this study 12 speakers produced sentences containing matched sets of words with initial vowels ranging from stressed to reduced, at normal and at fast speech rates. Measurements of the duration, intensity, F0, and spectral characteristics of the word-initial vowels showed that unstressed unreduced vowels differed significantly from both stressed and reduced vowels. This result held true across speaker sex and dialect. The vowels produced by one speaker were then cross-spliced across the words within each set, and the resulting words' acceptability was rated by listeners. In general, cross-spliced words were only rated significantly less acceptable than unspliced words when reduced vowels interchanged with any other vowel. Correlations between rated acceptability and acoustic characteristics of the cross-spliced words demonstrated that listeners were attending to duration, intensity, and spectral characteristics. Together these results suggest that unstressed unreduced vowels in English pattern differently from both stressed and reduced vowels, so that no acoustic support for a binary categorical distinction exists; nevertheless, listeners make such a distinction, grouping unstressed unreduced vowels by preference with stressed vowels.

Role of Helicobacter pylori serology in evaluating treatment success

Duodenal ulcer recurrence and gastritis are reduced with successful Helicobacter pylori treatment. Serology is accurate in the diagnosis of H. pylori, but its value in determining eradication is unproved. To evaluate the usefulness of serology in monitoring treatment, we measured serial serum antibodies in three patient groups: eradication success (N = 57), eradication failure (N = 19), and untreated patients (N = 24). Eradication was determined by Warthin Starry staining of antral biopsies and repeat 13C breath tests at six weeks. Subsequent 13C breath tests were then performed at three-month intervals to monitor eradication. IgG antibody concentrations to H. pylori were determined by a commercially available ELISA kit. Serology concentrations remained constant throughout the study period in the untreated patients. IgG concentrations decreased slightly in the treatment failure group at six weeks but thereafter remained at baseline values. In the eradicated group, serum IgG concentrations decreased 26% by three months, 43% by six months and 55% at nine and 12 months (P < 0.001). A 20% reduction in IgG concentrations by six months was associated with successful treatment (sensitivity 86% and specificity 88%). We conclude that serology is a potentially useful way to monitor H. pylori treatment success.

Infants' preference for the predominant stress patterns of English words

One critical aspect of language acquisition is the development of a lexicon that associates sounds and meanings; but developing a lexicon first requires that the infant segment utterances into individual words. How might the infant begin this process? The present study was designed to examine the potential role that sensitivity to predominant stress patterns of words might play in lexical development. In English, by far the majority of words have stressed (strong) initial syllables. Experiment 1 of our study demonstrated that by 9 months of age American infants listen significantly longer to words with strong/weak stress patterns than to words with weak/strong stress patterns. However, Experiment 2 showed that no significant preferences for the predominant stress pattern appear with 6-month-old infants, which suggests that the preference develops as a result of increasing familiarity with the prosodic features of the native language. In a third experiment, 9-month-olds showed a preference for strong/weak patterns even when the speech input was low-pass filtered, which suggests that their preference is specifically for the prosodic structure of the words. Together the results suggest that attention to predominant stress patterns in the native language may form an important part of the infant's process of developing a lexicon.

The monolingual nature of speech segmentation by bilinguals

Monolingual French speakers employ a syllable-based procedure in speech segmentation; monolingual English speakers use a stress-based segmentation procedure and do not use the syllable-based procedure. In the present study French-English bilinguals participated in segmentation experiments with English and French materials. Their results as a group did not simply mimic the performance of English monolinguals with English language materials and of French monolinguals with French language materials. Instead, the bilinguals formed two groups, defined by forced choice of a dominant language. Only the French-dominant groups showed syllabic segmentation and only with French language materials. The English-dominant group showed no syllabic segmentation in either language. However, the English-dominant group showed stress-based segmentation with English language materials; the French-dominant group did not. We argue that rhythmically based segmentation procedures are mutually exclusive, as a consequence of which speech segmentation by bilinguals is, in one respect at least, functionally monolingual.

Limits on bilingualism

Speech, in any language, is continuous; speakers provide few reliable cues to the boundaries of words, phrases, or ther meaningful units. To understand speech, listeners must divide the continuous speech stream into portions that correspond to such units. This segmentation process is so basic to human language comprehension that psycholinguists long assumed that all speakers would do it in the same way. In previous research, however, we reported that segmentation routines can be language-specific: speakers of English do not. French has relatively clear syllable boundaries and syllable-based timing patterns, whereas English has relatively unclear syllable boundaries and stress-based timing; thus syllabic segmentation would work more efficiently in the comprehension of French than in the comprehension of English. Our present study suggests that at this level of language processing, there are limits to bilingualism: a bilingual speaker has one and only one basic language.

A language-specific comprehension strategy

Infants acquire whatever language is spoken in the environment into which they are born. The mental capability of the newborn child is not biased in any way towards the acquisition of one human language rather than another. Because psychologists who attempt to model the process of language comprehension are interested in the structure of the human mind, rather than in the properties of individual languages, strategies which they incorporate in their models are presumed to be universal, not language-specific. In other words, strategies of comprehension are presumed to be characteristic of the human language processing system, rather than, say, the French, English, or Igbo language processing systems. We report here, however, on a comprehension strategy which appears to be used by native speakers of French but not by native speakers of English.