How the required precision influences the way we intercept a moving object

Do people perform a given motor task differently if it is easy than if it is difficult? To find out, we asked subjects to intercept moving virtual targets by tapping on them with their fingers. We examined how their behaviour depended on the required precision. Everything about the task was the same on all trials except the extent to which the fingertip and target had to overlap for the target to be considered hit. The target disappeared with a sound if it was hit and deflected away from the fingertip if it was missed. In separate sessions, the required precision was varied from being quite lenient about the required overlap to being very demanding. Requiring a higher precision obviously decreased the number of targets that were hit, but it did not reduce the variability in where the subjects tapped with respect to the target. Requiring a higher precision reduced the systematic deviations from landing at the target centre and the lag-one autocorrelation in such deviations, presumably because subjects received information about smaller deviations from hitting the target centre. We found no evidence for lasting effects of training with a certain required precision. All the results can be reproduced with a model in which the precision of individual movements is independent of the required precision, and in which feedback associated with missing the target is used to reduce systematic errors. We conclude that people do not approach this motor task differently when it is easy than when it is difficult.     

How we think about cognition, emotion, and biology in psychopathology

The variety of potential relationships assumed between psychological and biological concepts fosters considerable misunderstanding of what our data can tell us. A naively reductionistic view of psychological concepts is prevalent, particularly in the psychopathology literature. A series of examples of the application of psychophysiological methods in studies of cognition, emotion; and psychopathology provides a background for a discussion of these problems. Unwarranted distinctions between cognition and emotion, between classes of measures, and between psychological and biological approaches to understanding normal functioning and psychopathology undermine the ability of cognitive neuroscience to achieve its considerable potential. A nondualistic, nonreductionistic, noninteractive relationship is recommended, with psychological and biological concepts both having central, necessary, and distinct roles.     

Feeling our way in the dark

The papers by Pontecorvo et al., Kesner and Altman and Normile are considered with regard to their illuminating potential in an area dark and murky with research issues. While each of these papers contributes an interesting perspective and narrow beam of light, the collective darkness dissipated by their work remains small.     

The way of our errors: Theme and variations

Negative feedback, either internal or external, is a fundamental guide to human learning and performance. The neural system that underlies the monitoring of performance and the adjustment of behavior has been subject to multiple neuroimaging investigations that uniformly implicate the anterior cingulate cortex and other prefrontal structures as crucial to these executive functions. The present article describes a series of experiments that employed event-related potentials to study a variety of processes associated with internal or external feedback. Three medial-frontal negativities (error-related negativity, correct-response negativity, feedback-related negativity) are highlighted, each of which plays an important role in the monitoring and dynamic adjustment of behavior. Extensions of basic research on these ERPs to questions relevant to clinical-science are also provided.     

How Toll-like receptors signal: what we know and what we don't know

Signal transduction pathways activated by Toll-like receptors (TLRs) have continued to be a major focus of research for investigators interested in the initiation of innate immune responses and the induction of pro-inflammatory cytokines and type I interferons during infection. Biochemical details of the major signalling pathways have now been obtained, and the specific signalling pathways activated by different TLRs are being elucidated. New insights into the activation of IRF family members, notably IRF3, IRF5 and IRF7, have been obtained, and interesting spatiotemporal aspects of signalling by MyD88 leading to IRF7 activation revealed. Adapters in TLR signalling are targets for inhibition, both by endogenous regulators and by virally derived proteins. Selective targeting of pathways by anti-inflammatory glucocorticoids also indicates the potential for modulating TLR signalling therapeutically.     

如何提高医学科技论文的投稿命中率

怎样提高投稿命中率,避免经常遭遇退稿的尴尬,是许多作者较为关注的一个文题。本文作者以编辑的身份,从投稿、选题、撰写、与编辑部建立联系几个方面,简要论述了个人的看法,以引起投稿者的注意。     

Bright light treatment: are we keeping our subjects in the dark?

Bright light treatments for seasonal affective disorder (SAD) and phase-disturbed circadian rhythms show considerable interindividual variation in response. Many studies have explained this variation in terms of traditional explanations of response variance, i.e., poor diagnostic criteria, poor compliance, etc. This study examined proximity and gaze behavior during illumination as a source of variance in response. Distance from the light source and gaze were varied systematically in order to quantify the discrepancy between perceived and transmitted light. The results indicate that the discrepancy between perceived and transmitted light increases rapidly as a function of distance and gaze. At best, subjects exposed to a transmitted illuminance of 10,000 lux perceived only 20% of the transmitted light, and this dropped rapidly to between 1 and 2% when subjects were more than 3 feet away and not gazing directly at the light source. These results suggest that light treatment protocols may be compromised by lack of attention to compliance and administration factors. These issues may account for much of the response variance observed previously.     

Skin immunity: dissecting the complex biology of our body's outer barrier

Our skin contributes critically to health via its role as a barrier tissue, carefully regulating passage of key substrates while also providing defense against exogenous threats. Immunological processes are integral to almost every skin function and paramount to our ability to live symbiotically with skin commensal microbes and other environmental stimuli. While many parallels can be drawn to immunobiology at other mucosal sites, skin immunity demonstrates unique features that relate to its distinct topography, chemical composition and microbial ecology. Here we provide an overview of skin as an immune organ, with reference to the broader context of mucosal immunology. We review paradigms of innate as well as adaptive immune function and highlight how skin-specific structures such as hair follicles and sebaceous glands interact and contribute to these processes. Finally, we highlight for the mucosal immunology community a few emerging areas of interest for the skin immunity field moving forward.     

Coeliac artery compression syndrome: can we believe our ears?

Two patients with coeliac artery compression syndrome' are described.

Symptoms were vague and nonspecific, and the diagnosis was made by finding an epigastric bruit on auscultation of the abdomen and confirming the presence of a vascular lesion by angiography. Both patients were cured by surgical decompression of the coeliac trunk. Auscultation of the abdomen can be a useful part of physical examination in general practice.

     

Losing culture on the way to competence: the use and misuse of culture in medical education.

Most cultural competence programs are based on traditional models of cross-cultural education that were motivated primarily by the desire to alleviate barriers to effective health care for immigrants, refugees, and others on the sociocultural margin. The main driver of renewed interest in cultural competence in the health professions has been the call to eliminate racial and ethnic disparities in the quality of health care. This mismatch between the motivation behind the design of cross-cultural education programs and the motivation behind their current application creates significant problems. First, in trying to define cultural boundaries or norms, programs may inadvertently reinforce racial and ethnic biases and stereotypes while doing little to clarify the actual complex sociocultural contexts in which patients live. Second, in attempting to address racial and ethnic disparities through cultural competence training, educators too often conflate these distinct concepts. To make this argument, the authors first discuss the relevance of culture to health and health care generally, and to disparities in particular. They then examine the concept of culture, paying particular attention to how it has been used (and misused) in cultural competence training. Finally, they discuss the implications of these ideas for health professions education.