Vergence effects on the perception of motion-in-depth

When the eyes follow a target that is moving directly towards the head they make a vergence eye movement. Accurate perception of the target's motion requires adequate compensation for the movements of the eyes. The experiments in this paper address the issue of how well the visual system compensates for vergence eye movements when viewing moving targets. We show that there are small but consistent biases across observers: When the eyes follow a target that is moving in depth, it is typically perceived as slower than when the eyes are kept stationary. We also analysed the eye movements that were made by observers. We found that there are considerable differences between observers and between trials, but we did not find evidence that the gains and phase lags of the eye movements were related to psychophysical performance.</p

Serum leptin in disabled and non-disabled children in an Indian slum population.

OBJECTIVE: To assess the concentration of serum leptin in a population of malnourished children and to compare the leptin levels of disabled and non-disabled children in this population. DESIGN: Case-control study. SUBJECTS: Eighty-one children, comprising 41 children with mixed disabilities and 40 non-disabled controls, were selected from 425 children involved in a case-control study assessing the nutritional status of children with disabilities in an Indian slum population. METHODS: Leptin was measured in the serum samples and was compared with anthropometry (weight-for-age Z-scores (WAZ), height-for-age Z-scores (HAZ), weight-for-height Z-scores (WHZ), body mass index (BMI), mid-upper-arm circumference (MUAC), sub-scapular skinfold thickness and triceps skinfold thickness) and serum acute phase proteins. RESULTS: The children were very malnourished with WAZ=-2.07 (s.d. 1.15), HAZ=-2.15 (s.d. 1.85) and WHZ=-1.07 (s.d. 0.83). Leptin was extremely low in both the disabled (1.44 ng/ml; 95% confidence interval, CI, 1.23-1.69) and the non-disabled (1.19 ng/ml; 95% CI 1.04-1.35) children. There were no differences between the disabled and non-disabled groups as a whole but 15 children with neurological disabilities had significantly higher (P<0.05) serum leptin (1.65 ng/ml; 95% CI 1.29-2.06) than the non-disabled children. Girls (1.55 ng/ml; 95% CI 1.29-1.87) had significantly higher concentrations of leptin than boys (1.11 ng/ml; 95% CI 1.02-1.22; P=0.002). Leptin did not correlate with any biochemical or anthropometric measures. CONCLUSIONS: In this population, where malnutrition was common, serum leptin levels were very low and did not correlate with anthropometry. SPONSORSHIP: UK Department for International Development; Virgin Airways through the Great Ormond Street Hospital Trustees

Retention of knowledge and perceived relevance of basic sciences in an integrated case-based learning (CBL) curriculum

Background: Knowledge and understanding of basic biomedical sciences remain essential to medical practice, particularly when faced with the continual advancement of diagnostic and therapeutic modalities. Evidence suggests, however, that retention tends to atrophy across the span of an average medical course and into the early postgraduate years, as preoccupation with clinical medicine predominates. We postulated that perceived relevance demonstrated through applicability to clinical situations may assist in retention of basic science knowledge.\ud \ud Methods: To test this hypothesis in our own medical student cohort, we administered a paper-based 50 MCQ assessment to a sample of students from Years 2 through 5. Covariates pertaining to demographics, prior educational experience, and the perceived clinical relevance of each question were also collected.\ud \ud Results: A total of 232 students (Years 2–5, response rate 50%) undertook the assessment task. This sample had comparable demographic and performance characteristics to the whole medical school cohort. In general, discipline-specific and overall scores were better for students in the latter years of the course compared to those in Year 2; male students and domestic students tended to perform better than their respective counterparts in certain disciplines. In the clinical years, perceived clinical relevance was significantly and positively correlated with item performance.\ud \ud Conclusions: This study suggests that perceived clinical relevance is a contributing factor to the retention of basic science knowledge and behoves curriculum planners to make clinical relevance a more explicit component of applied science teaching throughout the medical course