Neural activity in early visual cortex reflects behavioral experience and higher-order perceptual saliency.

We report here that shape-from-shading stimuli evoked a long-latency contextual pop-out response in V1 and V2 neurons of macaque monkeys, particularly after the monkeys had used the stimuli in a behavioral task. The magnitudes of the pop-out responses were correlated to the monkeys' behavioral performance, suggesting that these signals are neural correlates of perceptual pop-out saliency. The signals changed with the animal's behavioral adaptation to stimulus contingencies, indicating that perceptual saliency is also a function of experience and behavioral relevance. The evidence that higher-order stimulus attributes and task experience can influence early visual processing supports the notion that perceptual computation is an interactive and plastic process involving multiple cortical areas.

Clinical academies: innovative school-health services partnerships to deliver clinical education.

During the past five years (2001-2006), the University of Bristol Medical School has developed and implemented a new model for delivering clinical education: the clinical academy. The principal features of the model are (1) having both in-Bristol and out-of-Bristol campuses for clinical education, (2) innovative partnerships with local health care providers, (3) local leadership of educational delivery, and (4) the recruitment and training of new cadres of clinical teachers. The seven clinical academies consist of two academies based in traditional acute-care teaching hospitals in the city of Bristol and five academies in the surrounding counties. The same Bristol curriculum is delivered in every clinical academy by locally recruited hospital specialists and family physicians. Each academy is led by an academy medical dean, who has local responsibility for program delivery, quality assurance, academic and personal support for students, and finances on behalf of the university. Medical students rotate between clinical academies every half academic year, alternately based in and outside of Bristol. They learn clinical medicine and develop clinical competence as apprentice members of a local multiprofessional learning community. The medical school now has enough high-quality clinical placements to accommodate increasing numbers of medical students whilst keeping a "human-scale" educational environment. Clinical academies are thus the key components of a decentralized system of curriculum delivery; they differ in concept and purpose from the new academies of medical educators in the United States that offer a centralized focus for the educational mission.

Development and validation of a questionnaire for anxiety and depression in Pakistan.

BACKGROUND: Currently clinicians and researchers in Pakistan have to use translated western instruments to screen for anxiety and depressive disorders. This study investigated the local idioms of emotional distress in Pakistan to develop a culturally valid and easy-to-use instrument to screen for common mental disorders in general clinical settings. METHODS: A systematic survey was conducted of psychiatric case notes of patients attending clinics in Peshawar and Lahore, diagnosed with anxiety or depressive disorders, to identify the range of common idioms of psychological distress. A pilot version of the questionnaire was refined and validated among a composite sample of 330 patients in inpatient, outpatient and rural community settings. ICD-10 Diagnostic Criteria for Research were used to define cases and patients' relatives acted as normal controls. RESULTS: The pilot version of the questionnaire was reduced to 42 items based on odds ratios between cases and controls. Anxiety symptoms were generally reported by depressed patients, but not vice versa. Finally 30 items were selected, in two sub-scales. This final version achieved sensitivity, specificity, and positive and negative predicted values of over 90% when comparing cases and controls. LIMITATIONS: This questionnaire was based on what patients tell doctors and may not capture the entire repertoire of local idioms of distress. The validation study was conducted only in an Urdu/Punjabi speaking population, in Lahore and surrounding areas. CONCLUSIONS: The Pakistan Anxiety and Depression Questionnaire consists of an anxiety/depression scale and a depression scale, each of 15 items. It demonstrates excellent validity as screening instrument for anxiety and depressive disorders in clinical settings in Pakistan.

Modeling and decoding motor cortical activity using a switching Kalman filter.

We present a switching Kalman filter model for the real-time inference of hand kinematics from a population of motor cortical neurons. Firing rates are modeled as a Gaussian mixture where the mean of each Gaussian component is a linear function of hand kinematics. A "hidden state" models the probability of each mixture component and evolves over time in a Markov chain. The model generalizes previous encoding and decoding methods, addresses the non-Gaussian nature of firing rates, and can cope with crudely sorted neural data common in on-line prosthetic applications.

Associations of family support, resiliency, and depression symptoms among indigent teens attending a family planning clinic.

The goal of this study was to examine the effect of resiliency and family support on depression symptoms among 110 indigent adolescents attending a family planning clinic in a large urban city in southwestern USA. Findings suggested that several of the resiliency domains, on the Individual Protective Factors Index, as well as family support measured by the Family Support Scale, were associated with depression symptoms. Scores on the self-concept and positive outlook dimensions of the Personal Competence domain, the confidence and assertiveness dimensions of the Social Competence domain, and family support correlated with depression symptoms. The findings also suggested that 16.4% of the teens in this clinic would be classified as clinically depressed and as needing further evaluation. It seems reasonable to conclude that resilient adolescents may possess characteristics, beliefs, and supports which enable them to cope with life stressors more effectively and avoid depressive symptoms than those who are not as resilient. Given the prevalence and extent of depression among adolescents, it is important to develop interventions to foster attachment and enhance individual protective factors in primary prevention programs as such interventions may ameliorate the effects of high-risk environments.

Laparoscopic gastric banding is safe in outpatient surgical centers.

BACKGROUND: Due to constraints on resources and capacity, as well as advances in surgical technique and care, there has been progressive change toward converting surgical procedures to the outpatient setting when feasible. This study was designed to investigate the safety of laparoscopic adjustable gastric banding (LAGB) as an outpatient procedure for morbid obesity in Canada. METHODS: This retrospective analysis included consecutive patients who underwent outpatient LAGB at the Surgical Weight Loss Centre in Ontario, Canada, beginning with our initial experience in February 2005 and continuing to July 2009. Eligible patients were morbidly obese adults whose outpatient clinic surgery had been performed by one of two experienced surgeons. RESULTS: A total of 1,641 patients were included in this analysis. The average presurgical body mass index was 46.7 kg/m2 (range 35.0 to 79 kg/m2). Fifteen patients (0.91%) experienced minor complications during surgery or within 30 days of surgery (dysphagia, n=5; wound infection, n=3; port infection, n=2; all other complications occurred in one patient each). Four patients required transfer to hospital from the clinic on the day of surgery, and three were admitted. None of the complications were serious and all were resolved. The device was explanted in two patients. The average time from sedation to discharge was <4 hours (h). CONCLUSIONS: The ability to treat patients within 4 h and the extremely low complication rates reported here contribute to a growing literature supporting the safe performance of LAGB in an outpatient setting for the treatment of morbid obesity.

Recruitment into psychiatry.

BACKGROUND: Despite improvements in psychiatric teaching, British medical schools have never produced enough graduands aiming for psychiatry. AIMS: To inform the strategy for improving recruitment. METHOD: A literature review. RESULTS: The number of psychiatrists required depends on the role of psychiatry, which is constantly changing. The present requirement is about 250-300 per year, including replacements and new posts. The number of psychiatric trainees has always been higher than expected from the career plans of newly qualified doctors, but the number of British graduates passing the Royal College of Psychiatrists' Membership examination has still fallen short, requiring a supplement of foreign medical graduates. The recent 50% expansion in medical students may make this country self-sufficient. CONCLUSIONS: To improve recruitment, the College should focus on influences before and after undergraduate training - the kind of student entering medical school and the factors favouring sustained psychiatric practice after graduation.

Hierarchical Bayesian inference in the visual cortex.

Traditional views of visual processing suggest that early visual neurons in areas V1 and V2 are static spatiotemporal filters that extract local features from a visual scene. The extracted information is then channeled through a feedforward chain of modules in successively higher visual areas for further analysis. Recent electrophysiological recordings from early visual neurons in awake behaving monkeys reveal that there are many levels of complexity in the information processing of the early visual cortex, as seen in the long-latency responses of its neurons. These new findings suggest that activity in the early visual cortex is tightly coupled and highly interactive with the rest of the visual system. They lead us to propose a new theoretical setting based on the mathematical framework of hierarchical Bayesian inference for reasoning about the visual system. In this framework, the recurrent feedforward/feedback loops in the cortex serve to integrate top-down contextual priors and bottom-up observations so as to implement concurrent probabilistic inference along the visual hierarchy. We suggest that the algorithms of particle filtering and Bayesian-belief propagation might model these interactive cortical computations. We review some recent neurophysiological evidences that support the plausibility of these ideas.