The kinaesthetic perception of Euclidean distance: a study of the detour effect

An experiment investigated the mechanisms by which humans estimate Euclidean distances on the basis of kinaesthetic cues. Blindfolded participants followed straight and curvilinear paths with a hand-held stylus (encoding phase). Then, with a straight movement, they estimated the Euclidean distance between the start- and end-points of the path (response phase). The experiment contrasted an On-axis condition, in which encoding and response movements were spatially aligned, and an Off-axis condition, in which they were displaced laterally. Performances were slightly more accurate in the On-axis condition than in the Off-axis condition. In both conditions, however, errors were consistently smaller when the path covered a larger surface. The results showed that small paths yielded an overestimation of the Euclidean distance, the relative errors increasing with the length of curvilinear paths. The findings are compared with results of other studies in which distances were estimated on the basis of haptic cues.     

Factors related to correspondence between teacher ratings of elementary student depression and student self-ratings.

Fourth through sixth graders (n = 418) completed the Children's Depression Inventory (CDI; Kovacs, 1980). Each teacher (n = 31) rated 6 students with high, low, or medium CDI scores (n = 181) using the CDI items (teacher-CDI) and a single global rating. Remaining students received the global rating only. Sixteen teachers were randomly assigned to receive instruction on childhood depression. Contrary to earlier studies, moderate correspondence was found for both measures. Familiarity was related to correspondence, whereas confidence and student gender were unrelated to correspondence. Instruction improved knowledge, but not correspondence. School-related behaviors yielded the highest correspondence. The teacher-CDI displayed high test-retest reliability.     

Investigating the effect of a transparent barrier on the crossmodal congruency effect

A transparent barrier, such as a window, protects us from approaching objects (such as flies), although we can still see the objects coming toward us through the occluder. In the present study, we examined whether this potential dissociation between tactile and visual experience introduced by the presence of a transparent barrier also affects visual-tactile interactions in normal participants, as indexed by performance in the crossmodal congruency task. Participants discriminated the elevation of vibrotactile target stimuli (upper vs lower) presented to the left or right hand while trying to ignore visual distractor lights that could independently be presented from upper or lower locations on either the same or the opposite side. A transparent occluder was placed between the vibrotactile targets and the visual stimuli (the barrier occluded the vibrotactile targets in Experiment 1 and the visual distractors in Experiment 2). Vibrotactile elevation discrimination performance was slower and less accurate when the distractor lights were presented from incongruent locations relative to the target (e.g., lower tactile target with upper distractor light). However, there were no significant differences between performance with and without the transparent occluder present. This pattern of results was replicated in Experiment 3 under conditions where the participants were periodically required to reach around the transparent occluder in order to press buttons placed near to the visual distractors. Taken together, these results support recent neuropsychological evidence [Farne et al. (2003) Int J Psychophysiol 50:51-61] suggesting that visual-tactile interactions in peripersonal space are not necessarily modulated by conscious awareness of the impossibility of our hand being touched by the visual stimuli.     

Factors affecting the size of the detour effect in the kinaesthetic perception of Euclidean distance

Three experiments investigated the mechanisms by which we estimate Euclidean distances on the basis of kinaesthetic cues. In all experiments, blindfolded participants followed straight and curvilinear paths with a stylus. Then, with a straight response movement, they estimated the distance between the end-points of the previously explored path. Experiment 1 was designed to validate the hypothesis—made on the basis of results from a previous study—that errors in the kinaesthetic estimations of distances (detour effect) originate from the difficulty to decompose the displacement vector into relevant and irrelevant components, which would become more severe at points of inflection. Using elliptic paths (no inflections), we demonstrated that errors are indeed reduced considerably. The role of the orientation of the work plane was investigated in Experiment 2 in which the same paths used in our previous study were oriented in the frontal rather than the horizontal plane. The results indicate that the detour effect is independent of the orientation. Moreover, despite the asymmetry that gravity introduces between upward and downward movements, errors in the two directions are almost identical. Experiment 3 addressed two issues. First, we demonstrated that introducing a delay between the exploration of the path and the response did not alter significantly the pattern of errors. By contrast, we demonstrated that errors are severely reduced when the number of paths to be explored is reduced by half. The results of the three experiments are discussed within the context of current theories of sensori-motor coding.     

Semantic priming effect on the perception of a Kanji

A priming experiment was conducted to investigate how semantic context affects the perception of a briefly exposed Kanji target. On each trial, a Kanji or a plus (neutral) was presented as the prime stimulus for 1 s. When the prime was a Kanji, subjects were required to imagine any compound word, the first letter of which was to be that prime. After a blank of 500 ms, a target Kanji was briefly exposed followed by a patterned mask and two response alternatives, one of which the subject was asked to choose. The duration of the target was so adjusted that each subject could respond correctly at approximately 75% level. The % choice response was higher when the prime and the target made up a compound word (related condition) and also matched to the imagined word (facilitation) than when not (neutral condition). When the prime and the target were unrelated, the performance was the worst (inhibition). In the related condition, however, responses were more accurate even when the prime-target pair did not match to the imagined compound word than in the unrelated condition. These results suggest that semantic priming effect occurs automatically regardless of whether the subject may expect the target or not.     

Investigating human audio-visual object perception with a combination of hypothesis-generating and hypothesis-testing fMRI analysis tools

Primate multisensory object perception involves distributed brain regions. To investigate the network character of these regions of the human brain, we applied data-driven group spatial independent component analysis (ICA) to a functional magnetic resonance imaging (fMRI) data set acquired during a passive audio-visual (AV) experiment with common object stimuli. We labeled three group-level independent component (IC) maps as auditory (A), visual (V), and AV, based on their spatial layouts and activation time courses. The overlap between these IC maps served as definition of a distributed network of multisensory candidate regions including superior temporal, ventral occipito-temporal, posterior parietal and prefrontal regions. During an independent second fMRI experiment, we explicitly tested their involvement in AV integration. Activations in nine out of these twelve regions met the max-criterion (A??V) for multisensory integration. Comparison of this approach with a general linear model-based region-of-interest definition revealed its complementary value for multisensory neuroimaging. In conclusion, we estimated functional networks of uni- and multisensory functional connectivity from one dataset and validated their functional roles in an independent dataset. These findings demonstrate the particular value of ICA for multisensory neuroimaging research and using independent datasets to test hypotheses generated from a data-driven analysis.     

The influence of teacher support on student adjustment in the middle school years: a latent growth curve study

The influence of perceived teacher support on trajectories of depression and self-esteem in middle school was examined using multigroup latent growth cross-domain models. A longitudinal sample of 2,585 students was followed from the sixth through the eighth grades. Students' perceptions of teacher support and general self-esteem declined and depressive symptoms increased over the course of middle school. We further found that, for both boys and girls, changes in perceptions of teachers' support reliably predicted changes in both self-esteem and depression. In particular, those students perceiving increasing teacher support showed corresponding decreases in depressive symptoms and increases in self-esteem. Gender differences were found for the initial levels of both perceptions of teacher support and general self-esteem. A competing model was also tested, which gave additional support for pathways of influence from perceptions of teacher support to depression and self-esteem, rather than the reverse. This study underscores the role of teacher support in facilitating students' adjustment to middle school and highlights the importance of using idiographic methodologies in the study of developmental processes. Implications and future directions are discussed.     

多媒体教学现状的调查与分析

多媒体技术是通信、传播技术和计算机技术融为一体，并可人机交互对其进行综合处理的一门技术。以教学设计为基础、教学实施为目的的多媒体组合教学(multimedia teaching method)已广泛应用。作者对多媒体教学进行了调查分析，现报告如下。     

Elementary student and teacher perceptions of a mindfulness and yoga-based program in school: A qualitative evaluation

Research questionWhat are the qualitative insights and perspectives about the implementation of a mindfulness and yoga-based program from elementary youth and teachers?ContextA mindfulness and yoga-based curriculum was implemented in 15 schools. The curriculum was taught to students during a physical education or dance class by instructors who were within each school and received training on the curriculum.Sample selectionVolunteer focus group elementary students who participated for one year and teachers who did not implement the program were qualitatively interviewed, by three trained University researchers.Data collectionNine focus groups were completed within three different elementary schools. Six focus groups were completed with 3rd and 5th grade students. Three focus groups were conducted with teachers within each school which received the program, excluding instructors.AnalysisFocus group data were coded and a thematic analysis was completed among the 40 students and 23 teachers.Interpretation and main resultsTeachers had varying degrees of involvement with the program and communication emerged as a critical theme for buy-in as communication represents the underpinnings of creating and retaining stakeholders. Most students talked about perceived improvements in focus, emotional regulation, flexibility, breathing, and school work. A common theme to describe benefits of the program emerged with the idea of “increased focus”. Conceptually, it may be that increasing mindfulness increases “focus” thus increasing positive outcomes. More research is needed to understand if “focus” may serve as a mediating variable on emotional regulation, cognitive improvements, and other health outcomes.     

Evaluation of the effect of visceral fat area on the distance and angle between the superior mesenteric artery and the aorta

Purpose  To investigate the effect of visceral fat area on the distance and angle between the superior mesenteric artery (SMA) and the aorta. Methods  On axial and sagittal images from abdomen CT scan, the distance and the angle between the SMA and the aorta were measured at the location where the third part of the duodenum crosses. The visceral fat area was calculated at the level of the umbilicus on the abdominal CT section. Body mass index was calculated. Results  For both genders, the correlation between the distance and visceral fat area was substantial (p < 0.001). For males, there was no statistically significant relationship between the angle and the visceral fat area. For females, the correlation between the angle and the visceral fat area was low but significant and positive (r = 0.25, p < 0.048). In addition, it was found that males have a greater proportion of visceral fat than females. In both females and males, the subcutaneous fat area correlated with BMI (r = 0.65, r = 0.69, respectively, p < 0.001), more strongly than the visceral fat area did (r = 0.51, r = 0.63, respectively, p < 0.001). Conclusions  The distance between the aorta and the SMA significantly correlates with visceral fat area than with BMI. The size of visceral fat area of females and males vary; therefore, the amount of visceral fat area should be considered in the establishing diagnosis of SMA syndrome.     

Relationships between thalamostriatal neurons and pedunculopontine projections to the thalamus: a neuroanatomical tract-tracing study in the rat

 The present study aimed to investigate whe- ther the pedunculopontine projection to the thalamus overlaps with identified thalamostriatal neurons. These projections were studied using a dual tract-tracing procedure combining anterogradely transported biotinylated dextran amine (pedunculopontine projections) and retrogradely transported Fluoro-Gold (thalamostriatal projections). Overlapping thalamic territories between thalamostriatal neurons and the axon terminals arising from the pedunculopontine tegmental nucleus were observed in the midline (paraventricular) and in the intralaminar (centrolateral, central medial, paracentral and parafasci- cular) thalamic nuclei. Other thalamic nuclei, such as the ethmoid, intermediodorsal, mediodorsal, paratenial, posteromedian, ventromedian, ventrolateral and rhomboid thalamic nuclei, displayed a lesser degree of overlap. These observations suggest the existence of presumptive contacts between thalamostriatal neurons and axons emerging from the pedunculopontine tegmental nucleus, therefore supporting the possible existence of feedback circuits in the rat basal ganglia in which the tegmentothalamic projection would play a major role. Received: 7 December 1998 / Accepted: 8 March 1999     

The gap between back pain patients' prior knowledge and scientific knowledge and its evolution after a back school teaching programme: a quantitative evaluation

This study presents a method for quantitative evaluation of the congruence between patients' representations and teachers' scientific knowledge, which is used as the standard of assessment. First, the patients' knowledge and the teachers' scientific concepts before a back school (BS) programme were compared (T₀). Then the evolution of patients' knowledge at 1 month (T₁) and 1 year (T₂) after the teaching was evaluated. Patients' knowledge was assessed blind by a multidisciplinary panel of nine independent judges. Mean scores were computed for each set of data (T₀, T₁, T₂); these scores were then submitted to an analysis of variance. The results showed an important gap between patients and teachers before BS with an improvement after the teaching. Knowledge referring to know-how and/or attitudes evolved differently when compared to theoretical knowledge.     

Quality assurance programme in haematology at a teaching hospital in the eastern region of Nepal

Quality assurance in haematology laboratory is intended to ensure the reliability of the laboratory tests. A quality assurance programme has two main aspects, namely, internal quality control and external quality assessment. A two year experience of quality assurance in haematology laboratory at B.P. Koirala Institute of Health Sciences, Nepal, is presented here. As a part of internal quality control, test results in the laboratory were scrutinized before release on a daily basis. Inconsistent result were checked for the given values with control material. In addition, the laboratory is a participant of the 'External Haematology Quality Assurance Programme' conducted by WHO regional reference centre at AIIMS, New Delhi, India. Variations related to errors in manual and autopipetting, calibration and inter-observer differences have been noted from time to time and rectified. The programme has helped us to deliver quality service in haematology laboratory at BPKIHS.     

The effect of cooling on the perception of carbohydrate and intensive sweeteners

The effect of cooling on the perceived intensity of sweetness was measured for four different compounds: glucose, fructose, aspartame and saccharin. Perceived sweetness was rated in a sip and spit paradigm when the taste solution, the tongue, or both were either held at 36 degrees C or cooled to 20 degrees C. It was discovered that for glucose and fructose perceived sweetness was significantly reduced by cooling, and that cooling the tongue reduced sweetness more than did cooling the solution. The perceived sweetness of aspartame was also lessened by cooling, but in that case the temperature of the tongue and the temperature of the solution had similar effects on sweetness. In contrast to the other compounds, the sweetness of saccharin was not affected by temperature. These results (when combined with data previously reported for sucrose) raise the possibility that as a group, carbohydrate sweeteners are affected similarly by temperature, whereas thermal effects on intensive sweeteners may be less predictable. The data thereby provide indirect support for the hypothesis that the sweet taste is mediated by more than one type of gustatory receptor.     

The effect of location of a highlight in a shaded circle on depth perception

Two experiments were performed to examine how the apparent depth of a shaded circle on a plane was affected by the direction and the distance of a highlight in the shaded area from the center of the circle. Fourteen undergraduates were asked to rate the concentrically shaded circle according to the apparent depth using the method of magnitude estimation. Experiment I showed that the rating was the highest in the upper-left, upper-right, and top conditions of the direction and the lowest in the bottom condition. Experiment 2 showed that the rating was the highest when the highlight was located at a third of the diameter of the circle apart from the center and the lowest when the highlight was on the edge of the circle or in the center. On the whole, the results support Ramachandran's "Assumption of Light From Above", which states that humans perceive a circle shaded bright in the top and dark in the bottom as convex due to their long experience on the earth since their birth.     

Investigating the barriers to teaching family physicians' and specialists' collaboration in the training environment: a qualitative study

Background  

Collaboration between physicians in different specialties is often taken for granted. However, poor interactions between family physicians and specialists contribute significantly to the observed discontinuity between primary and specialty care. The objective of this study was to explore how collaboration between family physicians and specialists was conceptualised as a competency and experienced in residency training curricula of four faculties of medicine in Canada.