Biomedical subjects

E Chun

Publications and source records attributed to E Chun.

7 recordsLinked to original sources

PubMed2000

Neighborhood frequency does affect performance in the Reicher task: encoding or decision?

Three experiments using the Reicher task show that performance on low-frequency words is disrupted if the incorrect alternative forms a higher frequency word. This neighborhood frequency effect occurs for both energy and pattern masks and for different sets of items. When the upcoming word is primed and its accessibility is enhanced, the neighborhood frequency effect is eliminated. Experiments 4a and 4b tested the neighborhood frequency effect using a same-different task and a signal-detection analysis. Neighborhood frequency affected the decision criterion but not the sensitivity of the perceptual system. Experiment 5 showed that many words with a frequency in the range from 1 to 5 per million are not recognized out of context. These results are consistent with the hypothesis that frequency effects in the Reicher task are caused by a bias in the decision system and can be simulated with the stochastic activation-verification model.

Adult↗

PubMed1999

Discrete threshold versus continuous strength models of perceptual recognition.

Two experiments were designed to test discrete-threshold models of letter and word recognition against models that assume that decision criteria are applied to measures of continuous strength. Although our goal is to adjudicate this matter with respect to broad classes of models, some of the specific predictions for discrete-threshold are generated from Grainger and Jacobs' (1994) Dual-Readout Model (DROM) and some of the predictions for continuous strength are generated from a revised version of the Activation-Verification Model (Paap, Newsome, McDonald, & Schvaneveldt, 1982). Experiment 1 uses a two-alternative forced-choice task that is followed by an assessment of confidence and then a whole report if a word is recognized. Factors are manipulated to assess the presence or magnitude of a neighbourhood-frequency effect, a lexical-bias effect, a word-superiority effect, and a pseudoword advantage. Several discrepancies between DROM's predictions and the obtained data are noted. Both types of models were also used to predict the distribution of responses across the levels of confidence for each individual participant. The predictions based on continuous strength were superior. Experiment 2 used a same-different task and confidence ratings to enable the generation of receiver operating characteristics (ROCs). The shapes of the ROCs are more consistent with the continuous strength assumption than with a discrete threshold.

Cognition↗

PubMed1999

Community health centers: unrecognized partners in health professions education.

Increasing demand for health professionals with training in ambulatory and primary care practice is placing stress on existing training site capacity. Community health centers can serve as model training sites, offering comprehensive multidisciplinary health care services and teaching clinician role models. In this study, 32 Illinois community and migrant health centers and federally qualified health centers were surveyed to asses their involvement with training in the past three years. Thirty centers had offered training to students from many disciplines, with nursing (27 centers) and medicine (24) the most frequent. Most centers had established formal relationships with training institutions but generally had limited involvement with course planning. Continued participation will likely require adequate funding, with some centers also seeking stronger institutional relationships and better integration of community health issues. Educators and policy makers may need to take a more active role in supporting centers, acquiring funds, and other enabling factors.

Clinical Competence↗

PubMed1996

Intramuscular prochlorperazine versus metoclopramide as single-agent therapy for the treatment of acute migraine headache.

To compare the efficacy of intramuscular prochlorperazine and metoclopramide in the short-term treatment of migraine headache in the emergency department 86 eligible adult patients with moderate to severe migraine headache were evaluated prospectively at a university-affiliated community hospital. After randomization, each subject received a 2-mL intramuscular injection of sterile saline, prochlorperazine (10 mg), or metoclopramide (10 mg). No other analgesics were administered during the 60-minute study period; patient assessment of relief was followed using visual analog scales. Reduction in median headache scores was significantly better among those treated with prochlorperazine (67%) compared to metoclopramide (34%) or placebo (16%). Similarly, symptoms of nausea and vomiting were significantly relieved in the prochlorperazine group (chi 2 = 17.1, P < .001). However, rescue analgesic therapy was necessary in the majority of patients treated with prochlorperazine (16/28) and metoclopramide (23/29) after the 60-minute study period. Although intramuscular prochlorperazine appears to provides more effective relief than metoclopramide, these results do not recommend either drug as single-agent therapy for acute migraine headache.

Acute Disease↗

PubMed1989

Lead increases red cell sodium-lithium countertransport.

The effect of 1, 3, 5, and 20 mumol/L lead on normal red cell sodium-lithium countertransport was studied in vitro. Red cell suspensions incubated with lead had increased sodium-lithium countertransport at all concentration levels compared with paired, unleaded controls when all groups were evaluated by analysis of covariance (F = 19.2, P less than 0.001). The effect of lead was concentration dependent (r = 0.998, P less than 0.001). These observations suggest that abnormalities in sodium transport are involved in the pathogenesis of lead-induced hypertension. Because increased red cell sodium-lithium countertransport is characteristic of essential hypertension, these observations further suggest that lead-induced and essential hypertension may share common pathophysiological mechanisms.

Antiporters↗

PubMedDate not supplied

Imaging of an unusual case of parasitic twinning.

Conjoined twins are rare in the literature and parasitic conjoined twins are rarer still. To our knowledge no cases of parasitic conjoined twins have previously been reported in the radiology literature. We present a case of parasitic conjoined twins in which radiographic findings played an important role in management.

Abnormalities, Multiple↗

PubMedDate not supplied

Identifying victims of elder abuse and neglect: a training video for prehospital personnel.

INTRODUCTION: The majority of prehospital emergency medical services (EMS) personnel lack specific training relating to elder abuse and neglect. OBJECTIVES: To develop and test an audio-visual training program that focuses on the identification and reporting of domestic violence in the elderly. METHODS: A videotape was designed to be used as a 45-minute training course for prehospital personnel using one-half inch, super-VHS recording. A convenience sample of 60 EMS personnel working in Kent County then were asked to evaluate the videotape program. Each volunteer completed a pre-test on elder abuse and neglect, watched the 45-minute videotape, and then answered 12 questions on a post-test. RESULTS: Participants had an average of 12.4 years (range: 1-30 years) prehospital emergency-care experience. Only four (7%) could recall any previous training relating to elder abuse or neglect during their careers. Although the prevalence of elder abuse in their community was described as "rather rare" by most (60%) of the subjects, 85% (51/60) had seen a suspected case of elder abuse or neglect during their careers; 47% (28/60) had seen a case during the past six months. Only 29% of these suspected cases were reported to county authorities. Approximately 40% of the questions on the pre-test were answered correctly (mean score, 4.8 +/- 3.0). In comparison, 83% of the questions on the post-test were answered correctly (10.0 +/- 3.0). Although participants had a number of suggestions to improve the video program, 78% (47/60) expected this material to change the way they will evaluate elderly patients in the future. CONCLUSION: Prehospital personnel do not feel confident identifying or reporting victims of elder abuse or neglect. A videotape training program may be an effective way of presenting this information as a means of continuing education.

Aged↗