Learning of blood pressure responses in the noncurarized rat: transfer to the curarized state.
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A sensorimotor sequence may contain information structure at several different levels. In this study, we investigated the hypothesis that two dissociable processes are required for the learning of surface structure and abstract structure, respectively, of sensorimotor sequences. Surface structure is the simple serial order of the sequence elements, whereas abstract structure is defined by relationships between repeating sequence elements. Thus, sequences ABCBAC and DEFEDF have different surface structures but share a common abstract structure, 123213, and are therefore isomorphic. Our simulations of sequence learning performance in serial reaction time (SRT) tasks demonstrated that (1) an existing model of the primate fronto-striatal system is capable of learning surface structure but fails to learn abstract structure, which requires an additional capability, (2) surface and abstract structure can be learned independently by these independent processes, and (3) only abstract structure transfers to isomorphic sequences. We tested these predictions in human subjects. For a sequence with predictable surface and abstract structure, subjects in either explicit or implicit conditions learn the surface structure, but only explicit subjects learn and transfer the abstract structure. For sequences with only abstract structure, learning and transfer of this structure occurs only in the explicit group. These results are parallel to those from the simulations and support our dissociable process hypothesis. Based on the synthesis of the current simulation and empirical results with our previous neuropsychological findings, we propose a neuro-physiological basis for these dissociable processes: Surface structure can be learned by processes that operate under implicit conditions and rely on the fronto-striatal system, whereas learning abstract structure requires a more explicit activation of dissociable processes that rely on a distributed network that includes the left anterior cortex.
Horseradish peroxidase (HRP) was injected into the first (SI) or second (SII) somatosensory areas of 21 adult cats. The radial and tangential (normal and parallel to the pial surface, respectively) distribution and morphology of the callosal neurons were studied. HRP injections were combined with single unit recording in the contralateral cortex in order to determine which part of the somatosensory periphery is represented within the regions containing callosal neurons, the callosal (efferent) zones, in SI and SII. The callosal zone of SI extends over the trunk and part of the forepaw representation. In the forepaw and hindlimb representations callosal neurons projecting only to the contralateral SII are found, while in the trunk representation callosal neurons projecting to contralateral SI or SII are found. The callosal zone in SII extends widely throughout the forepaw representation in this area and projects to the contralateral SII but not to SI. In both SI and SII the callosal neurons are mainly located in layer III. A few of them are also found in layer VI. They are very rare in other layers. Callosal neurons in layer III are mostly pyramidal but exceptionally stellate; in layer VI they are pyramidal, triangular, and occasionally stellate. These data indicate that transformations of the cortical somatosensory maps are achieved in the message sent through the corpus callosum. These transformations are i) determined by the extent and location of the callosal zones and perhaps by the distribution of callosal neurons within them, ii) different in different areas, iii) different in a same area, according to the cortical targets to which they are conveyed. The existence of callosal connections originated from areas of distal forepaw representation supplies a possible anatomical substrate for those types of intermanual transfer of tactile learning which depend upon the integrity of the corpus callosum.
The focus is on the basic biological-genetic and social-cultural architecture of human development across the life span. The starting point is the frame provided by past evolutionary forces. A first conclusion is that for modern times and the relative brevity of the time windows involved in modernity, further change in human functioning is primarily dependent on the evolution of new cultural forms of knowledge rather than evolution-based changes in the human genome. A second conclusion concerns the general architecture of the life course. Three governing lifespan developmental principles coexist. First, because long-term evolutionary selection evince a negative age correlation, genome-based plasticity and biological potential decrease with age. Second, for growth aspects of human development to extend further into the life span, culture-based resources are required at ever increasing levels. Third, because of age-related losses in biological plasticity and negative effects associated with some principles of learning (e.g., negative transfer), the efficiency of culture is reduced as lifespan development unfolds. Joint application of these principles suggests that the lifespan architecture becomes more and more incomplete with age. Three examples are given to illustrate the implications of the lifespan architecture outlined. The first is a general theory of development involving the orchestration of three component processes and their age-related dynamics: Selection, optimization, and compensation. The second example is theory and research on lifespan intelligence that distinguishes between the biology-based mechanics and culture-based pragmatics of intelligence and specifies distinct age gradients for the two categories of intellectual functioning. The third example considers the goal of evolving a positive biological and cultural scenario for the last phase of life (fourth age). Because of the general lifespan architecture outlined, this objective becomes increasingly difficult to achieve. In fact, for other reasons (such as the obsolescence created by rapid technological change) the 21st century can be considered as the century of the permanently incomplete mind. The advent of intervention genetics creates a new scenario with promise and despair. Promise because of the possibility to complete the biological-genetic architecture of the life course through a priori and a posteriori genetic engineering, despair because of a new schism created by the risk of dissociation of the time course of genetic intervention and cultural evolution. For the first time in history, humankind is truly in charge of it's biocultural "natural" destiny.
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Interocular transfer of the habituation to diffuse photic stimuli was demonstrated to be almost complete in pigeons. Birds submitted to visual Wulst ablation or supraoptic commissure lesion performed in much the same way. In contrast, when the tectal and posterior commissures were lesioned, pigeons failed to show interocular transfer of that learning process.
Part 2 delves more deeply into the program which the Macarthur Institute of Higher Education has implemented; a problem-based learning curriculum with the focus on self directed learning and the transfer of concepts and principles related to the various sciences associated with health care. Through exploration of specific patient problems students are able to integrate the components of the course using a process of enquiry. This new approach has implications for the student, the new graduate, the teacher/facilitator, the workforce and the recipients of nursing care. A broad overview of the impact of the new paradigm on nursing thus far is provided with a suggested model for formal evaluation of the program.
In a serial reaction time task, procedural memory was examined in Dissociative Identity Disorder (DID). Thirty-one DID patients were tested for inter-identity transfer of procedural learning and their memory performance was compared with 25 normal controls and 25 controls instructed to simulate DID. Results of patients seemed to indicate a pattern of inter-identity amnesia. Simulators, however, were able to mimic a pattern of inter-identity amnesia, rendering the results of patients impossible to interpret as either a pattern of amnesia or a pattern of simulation. It is argued that studies not including DID-simulators or simulation-free memory tasks, should not be taken as evidence for (or against) amnesia in DID.
BACKGROUND: Several studies have investigated the transfer of surgical trainees' skills acquired on surgical simulators to the operating room setting. The purpose of this study was to compare the effectiveness of two laparoscopic surgery simulators by assessing the transfer of skills learned on simulators to closely matched surgical tasks in the animal laboratory. STUDY DESIGN: In this post-test-only Control group study design, 46 surgically naive medical student volunteers were randomly assigned to one of three groups: Tower Trainer group (n = 16), LapSim group (n = 17), and Control group (n = 13). Outcomes measures included both time and accuracy scores on three laparoscopic tasks (Task 1: Grasp and Place; Task 2: Run the Bowel; Task 3: Clip and Cut) performed on live anesthetized pigs, and a global rating of overall performance as judged by four experienced surgeons. RESULTS: The Tower Trainer group performed significantly better than the Control group on 1 of 7 outcomes measures-Task 3: Time (p < 0.032), although the LapSim group performed significantly better than the Control group on 2 of 7 measures-Task 3: Time (p < 0.008) and Global score (p < 0.005). In comparing the two simulators, the LapSim group performed significantly better than the Tower Trainer group on 3 of 7 outcomes measures-Task 2: Time (p < 0.032), Task 2: Accuracy (p < 0.030) and Global score (p < 0.005), although the Tower Trainer group did not perform significantly better than the LapSim group on any measure. CONCLUSIONS: This study demonstrated that naive subjects trained on a virtual-reality part-task trainer performed better on live surgical tasks in a porcine model as compared with those trained with a traditional box trainer. These findings could aid in selection of appropriate training methodologies.
In the UK a number of high severity rail accidents, combined with structural change in the rail industry led to the need for revised accident investigation procedures. The revised procedure addressed identified issues with accident investigation, but to ensure maximum benefit in terms of identification of underlying causes of accidents and the production of good recommendations, training for rail industry accident investigators was required. The development of training followed the development of the revised procedure, with key decisions including the scope of the training and the delivery method that promotes the highest degree of information transfer and individual learning. The training has been delivered to the rail industry with considerable success but has, and continues, to face challenges as the industry structure continues to evolve.
Local authorities throughout the UK are refining or implementing curbside recycling schemes as they attempt to achieve challenging statutory recycling targets. Despite the importance of curbside schemes there are few published studies that have reported on actual measured levels and frequency of participation by residents, hindering transferability of lessons learned nationally and internationally. This paper reports measurements and analysis over at least four weeks for three different curbside recycling schemes operating in England, with at least 1400 samples in each. It is found that the participation rate is higher in schemes that collect more types of materials. Participation rates of 38%, 49% and 65% were measured for schemes that collected 1, 2 and 3 material types, respectively. The increase appears to be related not only to extra participants setting out the additional materials, but also increased participation for the common materials. It is found that for one scheme, more households tend to set out plastics and cans compared to newspapers.
When researching the literature, many differences within surgical techniques for breast conservation, tumour excision and axillary dissection are described in the smallest detail. Most authors have their own preferences but little clinical research has been done to evaluate the impact of those differences on outcome: local control, cosmesis, complications or costs. Even when prospective, randomized clinical trial protocols provide many instructions to perform the surgery, the case report forms almost never document the surgery actually performed. This is in contrast to radiotherapy and chemotherapy regimens, which have had higher standards of quality of care implemented. The development of more detailed and standardized procedural information should lead to more accurate and specific information, which can be easily transferred in a learning process, and enable more reliable clinical research. Documentation and guidelines for surgery are essential tools in implementing a process of quality audit for a type of surgery where accuracy is essential.
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An expectation of health care for young people with disability is that quality coordinated care continues to be available as they pass from the paediatric to the adult health care system. While individual clinicians provide this service well, the widespread absence of coordinated multidisciplinary care for young people with spina bifida in the adult health care system is a major deficiency. This paper describes the planning and implementation that underpinned the transfer of 10 young people with spina bifida from a paediatric to an adult service. The range of structural, financial and 'cultural' barriers that need to be overcome before patients can be successfully transferred is highlighted; lessons learned from this model may serve to facilitate the development of other transfer services.
OBJECTIVE: To assess the efficacy and safety of a new intraurethral sphincter prosthesis to treat hyporeflexic bladders in women. PATIENTS AND METHODS: Between July 1997 and December 1998, 18 women (mean age 45.8 years, range 26-84) with neurogenic voiding disorders and a hyporeflexic bladder were examined prospectively. All but one patient (who used the Crédé manoeuvre) emptied their bladder using clean intermittent catheterization. The women were fitted with a prosthesis consisting of a valve and a pump inside a short self-retaining silicone device, which was activated by a magnetic remote control unit. The evaluation before implantation comprised a medical history, a neurological evaluation, urodynamic recordings and urine cultures. The follow-up after implantation included a monthly clinical assessment, a symptom questionnaire, urine culture, ultrasonographic examinations and replacement of the device if necessary. Urine samples were also cultured if there was any discomfort or fever. RESULTS: At 16 months of follow-up, only six of 18 patients continued to use the implant (mean follow-up 9.6 months) and were satisfied. In 10 patients major incontinence around the catheter, or irritation, led to removal of the device. Two patients were unable to learn how to transfer to the toilet to empty their bladder; therefore, their implant was removed and they were treated with a suprapubic catheter. Two patients died from unrelated causes. Twelve patients had positive bacteriuria while fitted with the device; six of them became symptomatic. Usually, only symptomatic lower urinary tract infections were treated. Technical problems occurred often; 14 catheters showed technical dysfunction and had to be replaced early and three external remote control units broke for no reason. Despite normal short-term cystoscopic findings (three patients), long-term urethral damage cannot be excluded. Indeed, the six patients who remain fitted with the device already show some widening of their urethra. CONCLUSION: This experience with the new device was disappointing; in eight of the 18 patients incontinence appeared or worsened and led to removal of the device. Technical problems were common. The other concern is that significant long-term urethral damage could be expected, as observed with indwelling catheters over time. Thus, although this device may function for a short period, it is unsuitable for long-term use.