Fast and frugal models of clinical judgement in novice and expert physicians

Our objective was to study whether “compensatory” models provide better descriptions of clinical judgment than fast and frugal models, according to expertise and experience. Fifty practitioners appraised 60 vignettes describing a child with an exacerbation of asthma and rated their propensities to admit the child. Linear logistic (LL) models of their judgments were compared with a matching heuristic (MH) model that searched available cues in order of importance for a critical value indicating an admission decision. There was a small difference between the 2 models in the proportion of patients allocated correctly (admit or not-admit decisions), 91.2% and 87.8%, respectively. The proportion allocated correctly by the LL model was lower for consultants than juniors, whereas the MH model performed equally well for both. In this vignette study, neither model provided any better description of judgments made by consultants or by pediatricians compared to other grades and specialties.

Optic variables used to judge future ball arrival position in expert and novice soccer players

Although many studies have looked at the perceptual-cognitive strategies used to make anticipatory judgments in sport, few have examined the informational invariants that our visual system may be attuned to. Using immersive interactive virtual reality to simulate the aerodynamics of the trajectory of a ball with and without sidespin, the present study examined the ability of expert and novice soccer players to make judgments about the ball's future arrival position. An analysis of their judgment responses showed how participants were strongly influenced by the ball's trajectory. The changes in trajectory caused by sidespin led to erroneous predictions about the ball's future arrival position. An analysis of potential informational variables that could explain these results points to the use of a first-order compound variable combining optical expansion and optical displacement.

Visual outcomes of cataract surgery performed by supervised novice surgeons during training in rural China

To assess the outcomes of cataract surgery performed by novice surgeons during training in a rural programme. Design: Retrospective study. Participants: Three hundred thirty-four patients operated by two trainees under supervision at rural Chinese county hospitals. Methods: Two trainees performed surgeries under supervision. Visual acuity, refraction and examinations were carried out 3 months postoperatively. Main Outcome Measures: Postoperative uncorrected visual acuity, pinhole visual acuity, causes of visual impairment (postoperative uncorrected visual acuity<6/18) Results: Among 518 operated patients, 426 (82.2%) could be contacted and 334 (64.4% of operated patients) completed the examinations. The mean age was 74.1±8.8 years and 62.9% were women. Postoperative uncorrected visual acuity was available in 372 eyes. Among them, uncorrected visual acuity was ≥6/18 in 278 eyes (74.7%) and <6/60 in 60 eyes (16.1%), and 323 eyes (86.8%) had pinhole visual acuity≥6/18 and 38 eyes (10.2%) had pinhole visual acuity<6/60. Main causes of visual impairment were uncorrected refractive error (63.9%) and comorbid eye disease (24.5%). Comorbid eye diseases associated with pinhole visual acuity<6/60 (n=23, 6.2%) included glaucoma, other optic nerve atrophy, vitreous haemorrhage and retinal detachment. Conclusions: The findings suggest that hands-on training remains safe and effective even when not implemented in centralized training centres. Further refinement of the training protocol, providing postoperative refractive services and more accurate preoperative intraocular lens calculations, can help optimize outcomes. © 2012 The Authors Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

Judging the ‘passability’ of dynamic gaps in a virtual rugby environment

Affordances have recently been proposed as a guiding principle in perception–action research in sport (Fajen, Riley, & Turvey, 2009). In the present study, perception of the ’passability’ affordance of a gap between two approaching defenders in rugby is explored. A simplified rugby gap closure scenario was created using immersive, interactive virtual reality technology where 14 novice participants (attacker) judged the passability of the gap between two virtual defenders via a perceptual judgment (button press) task. The scenario was modeled according to tau theory (Lee, 1976) and a psychophysical function was fitted to the response data. Results revealed that a tau-based informational quantity could account for 82% of the variance in the data. Findings suggest that the passability affordance in this case, is defined by this variable and participants were able to use it in order to inform prospective judgments as to passability. These findings contribute to our understanding of affordances and how they may be defined in this particular sporting scenario; however, some limitations regarding methodology, such as decoupling perception and action are also acknowledged.

Detecting Deceptive Movement in 1 vs. 1 Based on Global Body Displacement of a Rugby Player

A key to success in many sports stems from the ability to anticipate what a player is going to do next. In sporting duels such as a 1 vs. 1 in rugby, the attacker can try and beat the defender by using deceptive movement. Those strategies involve an evolution of the centre of mass (COM) in the medio-lateral plane, from a minimal state to maximal displacement just before the final reorientation. The aim of this work is to consider this displacement as a motion-gap, as outlined in Tau theory, as a potential variable that may specify deceptive movement and as a means of comparing anticipatory performance between mid-level players and novices in rugby. Using a virtual reality set-up, 8 mid-level rugby players (ML) and 8 novices (NOV) observed deceptive (DM) and non-deceptive movements (NDM). The global framework used an occlusion time paradigm with four occlusion times. Participants had to judge the final direction of the attacker after the different cuts-off. For each movement and at each occlusion time, we coupled the ability to predict the good final direction with the value of the COM displacement in the medio-lateral (COM M/L) plane or with the Tau of this parameter (Tau COM). Firstly, results show that the Tau COM is a more predictive optical variable than the simple COM M/L. Secondly, this optical variable Tau COM is used by both groups, and finally, with a specific methodology we showed that mid-level players have significantly better anticipatory ability than the novice group.

The four I-model for scaffolding the professional development of experienced teachers in the use of virtual learning environments for classroom teaching.

Models of professional development for teachers have been criticized for not being embedded in the context in which teachers are familiar, namely their own classrooms. This paper discusses an adapted-Continuous Practice Improvement model, which qualitative findings indicate was effective in facilitating the transfer of creative and innovative teaching approaches from the expert or Resident Teacher’s school to the novice or Visiting Teachers’ classrooms over the duration of the project. The cultural shift needed to embed and extend the use of online teaching across the school was achieved through the positive support and commitment of the principals in the Visiting Teachers’ schools, combined with the success of the professional development activities offered by the Visiting Teachers to their school-based colleagues.

Expertise is perceived from both sound and body movement in musical performance

Music is a rich form of nonverbal communication, in which the movements that expert musicians make during performance can influence the perception of expressive and structural features of the music. Whether the actual skill of a musician is perceivable from vision of movement was examined. In Experiment 1, musicians and non-musicians rated performances by novice, intermediate and expert clarinettists from point-light animations of their movements, sound recordings, or both. Performances by clarinettists of more advanced skill level were rated significantly higher from vision of movements, although this effect was stronger when sound was also presented. In Experiment 2, movements and sound from the novice and expert clarinettists' performances were switched for half the presentations, and were matched for the rest. Ratings of novice music were significantly higher when presented with expert movements, although the opposite was not found for expert sound presented with novice movements. No perceptual effect of raters' own level of musicianship was found in either experiment. These results suggest that expertise is perceivable from vision of musicians' body movements, although perception of skill from sound is dominant. The results from Experiment 2 further indicate a cross-modal effect of vision and audition on the perception of musical expertise. © 2012 Elsevier B.V.

Detecting Deception in Movement: The Case of the Side-Step in Rugby

Although coordinated patterns of body movement can be used to communicate action intention, they can also be used to deceive. Often known as deceptive movements, these unpredictable patterns of body movement can give a competitive advantage to an attacker when trying to outwit a defender. In this particular study, we immersed novice and expert rugby players in an interactive virtual rugby environment to understand how the dynamics of deceptive body movement influence a defending player’s decisions about how and when to act. When asked to judge final running direction, expert players who were found to tune into prospective tau-based information specified in the dynamics of ‘honest’ movement signals (Centre of Mass), performed significantly better than novices who tuned into the dynamics of ‘deceptive’ movement signals (upper trunk yaw and out-foot placement) (p<.001). These findings were further corroborated in a second experiment where players were able to move as if to intercept or ‘tackle’ the virtual attacker. An analysis of action responses showed that experts waited significantly longer before initiating movement (p<.001). By waiting longer and picking up more information that would inform about future running direction these experts made significantly fewer errors (p<.05). In this paper we not only present a mathematical model that describes how deception in body-based movement is detected, but we also show how perceptual expertise is manifested in action expertise. We conclude that being able to tune into the ‘honest’ information specifying true running action intention gives a strong competitive advantage.

Gaze fixation improves the stability of expert juggling

Novice and expert jugglers employ different visuomotor strategies: whereas novices look at the balls around their zeniths, experts tend to fixate their gaze at a central location within the pattern (so-called gaze-through). A gaze-through strategy may reflect visuomotor parsimony, i.e., the use of simpler visuomotor (oculomotor and/or attentional) strategies as afforded by superior tossing accuracy and error corrections. In addition, the more stable gaze during a gaze-through strategy may result in more accurate movement planning by providing a stable base for gaze-centered neural coding of ball motion and movement plans or for shifts in attention. To determine whether a stable gaze might indeed have such beneficial effects on juggling, we examined juggling variability during 3-ball cascade juggling with and without constrained gaze fixation (at various depths) in expert performers (n = 5). Novice jugglers were included (n = 5) for comparison, even though our predictions pertained specifically to expert juggling. We indeed observed that experts, but not novices, juggled significantly less variable when fixating, compared to unconstrained viewing. Thus, while visuomotor parsimony might still contribute to the emergence of a gaze-through strategy, this study highlights an additional role for improved movement planning. This role may be engendered by gaze-centered coding and/or attentional control mechanisms in the brain.