BACKGROUND: When comparing a single-stroke dissection maneuver among surgeons with differing experience levels, there are major differences in the force applied to the instrument tip. It is difficult to explain to surgeons in training the appropriate force and for the surgeons to ascertain the force intuitively. We quantified the force pattern during single-stroke laparoscopic dissection maneuvers to reveal the factors related to expertise. METHODS: We recorded the force pattern of a single maneuver and measured the magnitude of vertical (VF) and horizontal forces (HF) on the instrument tip using a box trainer (ex vivo). We compared VF and HF among surgeons: experts (n = 10), intermediates (n = 10), and novices (n = 10). The dissection time of a single stroke (T), magnitude of the VF and HF, and the timing of the peak vertical force (TPV) and horizontal force (TPH) were evaluated as performance parameters. RESULTS: The dissection time of a single stroke (T) was shortest in the expert group (p < 0.05). The average maximum magnitude of VF and HF was smallest in the expert group. TPV occurred significantly earlier than TPH in all three groups (p < 0.05). TPV in the expert group occurred earlier than in the intermediate and novice groups (p < 0.05). With increasing experience, TPV occurred earlier. CONCLUSIONS: Expert surgeons apply the most efficient vertical forces to make an initial dissection point and then change to the horizontal direction to separate surrounding tissues from the target organ. Measuring instrument tip force could help in understanding and improving the safety margin in laparoscopic surgical dissection.
Face recognition is thought to rely on representations that encode holistic properties. Paradoxically, professional forensic examiners who identify unfamiliar faces by comparing facial images are trained to adopt a feature-by-feature comparison strategy. Here we tested the effectiveness of this strategy by asking participants to rate facial feature similarity prior to making same/different identity decisions to pairs of face images. Experiment 1 provided preliminary evidence that rating feature similarity improves unfamiliar face matching accuracy in novice participants. In Experiment 2, we found benefits of this procedure over and above rating similarity of personality traits and image quality parameters, suggesting that benefits are not solely attributable to general increases in attention. In Experiment 3, we then compared performance of trained forensic facial image examiners to novice participants, and found that examiners displayed: i) superior face matching accuracy; ii) smaller face inversion and feature inversion effects; and iii) feature ratings that were more diagnostic of identity. Further, aggregating feature ratings of multiple examiners produced perfect identity discrimination. Based on these quantitative and qualitative differences between experts and novices, we conclude that comparison based on local features confers specific benefits to trained forensic examiners. (PsycINFO Database Record
- European journal of sport science : EJSS : official journal of the European College of Sport Science
- Published about 7 years ago
Abstract We hypothesised that experienced runners would select a stride frequency closer to the optimum (minimal energy costs) than would novice runners. In addition, we expected that optimal stride frequency could simply be determined by monitoring heart rate without measuring oxygen consumption ([Formula: see text]O2). Ten healthy males (mean±s: 24±2 year) with no running training experience and 10 trained runners of similar age ran at constant treadmill speed corresponding to 80% of individual ventilatory threshold. For two days, they ran at seven different stride frequencies (self-selected stride frequency±18%) imposed by a metronome. Optimal stride frequency was based on the minimum of a second-order polynomial equation fitted through steady state [Formula: see text]O2 at each stride frequency. Running cost (mean±s) at optimal stride frequency was higher (P < 0.05) in novice (236±31 ml O2·kg(-1.)km(-1)) than trained (189±13 ml O2·kg(-1.)km(-1)) runners. Self-selected stride frequency (mean±s; strides(.)min(-1)) for novice (77.8±2.8) and trained runners (84.4±5.3) were lower (P < 0.05) than optimal stride frequency (respectively, 84.9±5.0 and 87.1±4.8). The difference between self-selected and optimal stride frequency was smaller (P < 0.05) for trained runners. In both the groups optimal stride frequency established with heart rate was not different (P > 0.3) from optimal stride frequency based on [Formula: see text]O2. In each group and despite limited variation between participants, optimal stride frequencies derived from [Formula: see text]O2 and heart rate were related (r > 0.7; P < 0.05). In conclusion, trained runners chose a stride frequency closer to the optimum for energy expenditure than novices. Heart rate could be used to establish optimal stride frequency.
Extensive studies have shown that a sports expert is superior to a sports novice in visually perceptual-cognitive processes of sports scene information, however the attentional and neural basis of it has not been thoroughly explored. The present study examined whether a sport expert has the attentional superiority on scene information relevant to his/her sport skill, and explored what factor drives this superiority. To address this problem, EEGs were recorded as participants passively viewed sport scenes (tennis vs. non-tennis) and negative emotional faces in the context of a visual attention task, where the pictures of sport scenes or of negative emotional faces randomly followed the pictures with overlapping sport scenes and negative emotional faces. ERP results showed that for experts, the evoked potential of attentional competition elicited by the overlap of tennis scene was significantly larger than that evoked by the overlap of non-tennis scene, while this effect was absent for novices. The LORETA showed that the experts' left medial frontal gyrus (MFG) cortex was significantly more active as compared to the right MFG when processing the overlap of tennis scene, but the lateralization effect was not significant in novices. Those results indicate that experts have attentional superiority on skill-related scene information, despite intruding the scene through negative emotional faces that are prone to cause negativity bias towards their visual field as a strong distractor. This superiority is actuated by the activation of left MFG cortex and probably due to self-reference.
Driving licensing jurisdictions require detailed assessments of fitness-to-drive from occupational therapy driver assessors (OTDAs). We developed decision training based on the recommendations of expert OTDAs, to enhance novices' capacity to make optimal fitness-to-drive decisions. The aim of this research was to determine effectiveness of training on novice occupational therapists' ability to make fitness-to-drive decisions.
Objective This study used a high-fidelity infant mannequin to examine the relationship between the quality of bag valve mask ventilation (BVMV) and how providers of varying levels of experience use visual feedback (e.g., electronic vital signs) to guide their performance. Background BVMV is a common and critical procedure for managing pediatric respiratory emergencies. However, providers do not consistently deliver effective BVMV. Efforts to improve BVMV have ignored the question of how providers effectively use feedback often available during BVMV. Method Six expert and six novice respiratory therapists completed two simulations of an infant requiring BVMV. In one, the technology failed to display SpO2, an important but somewhat redundant visual cue. Eye movements, verbal reports, and ventilation rate (in breaths per minute) were measured in each simulation. Results Regardless of SpO2 availability, eye movements and verbal reports suggested that novices depended strongly on electronic vital signs and when SpO2 was absent ventilated at a faster rate (exceeding the recommended range of ventilation rates) than when SpO2 was present. Experts' ventilation rates were comparable and within the recommended range in both conditions. When SpO2 was absent, experts emphasized information from direct observation of the patient that novices neglected. Conclusion Individual differences in the use of feedback during BVMV contribute to the quality of BVMV. This work bears on the theoretical discussions involving the use of automation and nontechnological cues to guide performance. Application These results have the potential to expand the current understanding of factors underlying effective BVMV with implications for training novice providers.
- International journal of computer assisted radiology and surgery
- Published over 2 years ago
Manipulation of the colonoscope is a technical challenge for novice clinicians which is best learned in a simulated environment. It involves the coordination of scope tip steering with scope insertion, using a rotated image as reference. The purpose of this work is to develop and validate a system which objectively assesses colonoscopy technical skills proficiency in an arbitrary training environment, allowing novices to assess their technical proficiency prior to real patient encounters.
This study examined the kinematic characteristics of disguised movements by applying linear discriminant (LDA) and dissimilarity analyses to the motion data from 788 disguised and 792 non-disguised 7-m penalty throws performed by novice and expert handball field players. Results of the LDA showed that discrimination between type of throws (disguised vs. non-disguised) was more error-prone when throws were performed by experts (spatial: 4.6%; temporal: 29.6%) compared to novices (spatial: 1.0%; temporal: 20.2%). The dissimilarity analysis revealed significantly smaller spatial dissimilarities and variations between type of throws in experts compared to novices (p<0.001), but also showed that these spatial dissimilarities and variations increased significantly in both groups the closer the throws came to the moment of (predicted) ball release. In contrast, temporal dissimilarities did not differ significantly between groups. Thus, our data clearly demonstrate that expertise in disguising one's own action intentions results in an ability to perform disguised penalty throws that are highly similar to genuine throws. We suggest that this expertise depends mainly on keeping spatial dissimilarities small. However, the attempt to disguise becomes a challenge the closer one gets to the action outcome (i.e., ball release) becoming visible.
The data described here provide standard performance measures following administration of a fingerprint matching task to expert analysts, trained students and novice control participants. Measures include accuracy on ‘same’ and ‘different’ trials, and the associated measures of sensitivity of discrimination (d') and response bias ©. In addition, speed of correct response is provided. The provision of these data will enable the interested reader to conduct meta-analyses relating to questions of fingerprint expertise and fingerprint training (see “Fact or friction: examination of the transparency, reliability and sufficiency of the ACE-V method of fingerprint analysis” (Stevenage and Pitfield, in press) ).
Ultrasound-guided techniques improve outcomes in regional anesthesia when compared with traditional techniques; however, this assertion has not been studied with novices. The primary objective of this study was to compare sensory and motor block after axillary brachial plexus block when performed by novice trainees allocated to an ultrasound- or nerve-stimulator-guided group. A secondary objective was to compare the rates of skill acquisition between the 2 groups.