Ranil Sonnadara

Changes in auditory cortex and the development of mismatch negativity between 2 and 6 months of age

Evoked responses to stimulus deviance were compared in infants between 2 and 6 months of age. A deviant stimulus containing a short silent gap occasionally replaced a repeating standard stimulus matched in duration, intensity and approximate spectral content. At two months, the standard stimuli evoked only a positive slow wave, and its amplitude was increased in response to the deviant stimuli. By 6 months, the deviant stimuli evoked an increased negativity at approximately 200 ms, similar to the mismatch negativity (MMN) response in adults. The results are considered with respect to layer-specific cortical maturation during this period.

Orthopedic boot camp: examining the effectiveness of an intensive surgical skills course.

BACKGROUND Changes in health care across the globe have had a profound impact on the number of hands-on surgical training opportunities that are available to residents. In the current study, we examine whether an intensive laboratory-based skills course at the start of orthopedic surgical training is an effective mechanism for teaching core technical skills. METHODS First-year residents were divided into 3 groups (on-service, n = 8; off-service, n = 8; and a new, competency-based program that has as a major element of the curriculum a focused, intensive skills laboratory-based experience, n = 6). Baseline surgical skills were assessed prior to commencing training. The intensive skills laboratory group was then given an intensive surgical skills course, whereas the other 2 groups embarked on traditional residency. After the surgical skills course, all the residents were assessed for core surgical skills using an objective structured assessment of technical skills (OSATS) procedure. RESULTS Pretraining scores revealed no differences between the groups of residents using both checklist (F[2,19] = 0.852, P = .442) and global rating scores (F[2,19] = 0.704, P = .507). Post-training scores revealed a significant difference, with residents from the intensive skills laboratory group performing better on both the checklists (on-service = 78.9, off-service = 78.6, intensive skills laboratory = 92.3; F[2,19] = 6.914, P < .01) and global rating scores (on-service = 3.4, off-service = 3.4, intensive skills laboratory = 4.3; F[2,19] = 5.722, P < .01), than the other groups who showed no differences between them. CONCLUSION The intensive skills course used in this study was highly effective at teaching and developing targeted surgical skills in first-year orthopedic residents. We predict that allowing residents to acquire key technical skills at the start of their training will enhance learning opportunities at later stages of training.

Measuring temporal resolution in infants using mismatch negativity

We show that the mismatch negativity (MMN) component of the event-related potential can be used to measure auditory temporal resolution in human infants. Infrequent stimuli with silent gaps of 4, 8, or 12 ms modulated the P2 component, generated MMN, and produced a P3a-like positivity. The data indicate that within-channel gap detection thresholds at 6 months are essentially at adult levels under conditions of little adaptation. Since MMN is elicited without attention and does not require a behavioural response, it can be measured similarly across the lifespan. We are now in a position to study the development of cross-channel temporal resolution and adaptation effects in infancy, and to examine how these abilities in infancy relate to later language acquisition.

Three-Year Experience with an Innovative, Modular Competency-Based Curriculum for Orthopaedic Training

In response to multiple stresses in current surgical education, we developed a new model of orthopaedic training that combines curricular reform with a competency-based framework. For the past three years, this pilot program has been run in parallel to our conventional curriculum for a select number of residents. In this article, we share our initial experience with this approach to training and describe its successes and challenges. We review the existing concerns with surgical training in a new era of work-hour restrictions and describe the pedagogical rationale for the model that we have developed. We then discuss the design of this curriculum, including the basic tenets and principles that guided our approach. Finally, we detail our preliminary results, which add evidence that a focused, modular-based program, with concentrated teaching of technical skills and frequent formative and summative evaluations, can result in rapid acceleration in surgical competency, knowledge acquisition, and comprehensive professional skills. This new model deserves further study and consideration for implementation on a broader scale in today’s challenging medical education environment. There have been questions about our general approach to surgical education for quite some time. Charles Bosk catalogued some of the good and much of the bad that went along with residency education a quarter of a century ago1. Similarly, William Nolan2 described the rigors of surgical training in Bellevue Hospital in New York, NY. The reverberations from The Bristol Royal Infirmary Inquiry3 sparked a focus on the issue of patient safety. This issue was reinforced with the dissemination of the Institute of Medicine report, To Err Is Human: Building a Safer Health System 4. Preoccupation with the issue of patient safety has led to many positive outcomes in patient care, but an important side effect has been decreased opportunities for residents for …

Effects of spatial separation and stimulus probability on the event-related potentials elicited by occasional changes in sound location

The ability to extract information about the spatial location of sounds plays an important role in auditory scene analysis. The present study examined the effects of spatial separation and stimulus probability on auditory event-related potentials (ERPs) to changes in sound location. In Experiment 1, we found that difference waves between ERPs elicited by standard and deviant stimuli showed a biphasic negative-positive response peaking around 126 and 226 ms after deviant onset. The amplitude of both responses increased with decreasing deviant stimulus probability, and increasing stimulus deviance. When the same stimuli were presented with equal probability for all locations (Experiment 2), there were no significant differences in the ERP amplitude and latency. These results suggest that the data reported in Experiment 1 are the result of contextual changes, rather than changes in simple acoustic features. Brain electrical source analyses are consistent with generators located in auditory cortices posterior to Heschels gyrus. Although occasional changes in sound location elicit earlier peaks than the mismatch negativity (MMN) response reported for other types of deviation, their topographical distribution and behavior are consistent with MMN. The early latency of MMN for changes in sound location is interpreted in the context of an early-warning system to alert the organism to new sound sources in the environment.

Reflections on Competency-Based Education and Training for Surgical Residents

Although a number of surgical training institutions have started to adopt competency-based education (CBE) frameworks for training, the debate about the value of this model continues. Some proponents regard CBE as a method of guaranteeing residents competence, whereas others consider CBE to be reductive and lacking the richness in experiences that the traditional model offers. In this article, we reflect on CBE and review some salient attempts to implement CBE in surgical education. We identify challenges facing postgraduate surgical education, some of which are motivating educators to consider incorporating CBE into their curricula. We look at some purported advantages and disadvantages of CBE and describe initial reports from CBE programs currently being developed.

Occasional changes in sound location enhance middle latency evoked responses

Rapid processing of sound location is critical for orienting attention. The present study investigated whether contextually sensitive early neural responses elicited by occasional changes in sound location could be measured. Using an oddball paradigm with stimuli consisting of brief noise bursts whose location was occasionally varied using head-related transfer functions, we found significant enhanced negativities in the event-related potentials elicited by deviant stimuli as early as 25 ms after stimulus onset, in addition to the differences around 125 ms which have previously been reported. Recent research suggests that occasional changes in auditory location information are processed in areas beyond primary auditory cortex. Our data suggest that any such processing is in fact preceded by activation in primary auditory cortex.

Orthopaedic Boot Camp II: Examining the retention rates of an intensive surgical skills course

BACKGROUND We examined retention rates for basic surgical skills taught through a 1-month intensive laboratory boot camp-style course at the onset of residency. METHODS We present data from 3 groups, each composed of 6 residents. The first group consisted of residents from a new competency-based curriculum (CBC). They started residency training with the Toronto Orthopaedic Boot Camp course. The other 2 groups were junior (JR) and senior (SR) residents from a traditional program whose residency training included no such course. Performance on targeted technical skills was tested using an objective structured assessment of technical skills examination 7 months after the onset of training for the CBC and JR groups and at least 43 months after the onset of training for the SR group. RESULTS The mean global rating scale score for the CBC group immediately after the skills course was 4.3, which was maintained 6 months later. There were no significant performance differences between the CBC and SR groups. Both the CBC and SR groups performed significantly better than the JR group (mean global rating scale 3.7; F[2, 15] = 12.269, P < .001). CONCLUSION We conclude that a surgical skills course at the onset of residency is an effective mechanism for teaching targeted technical skills and that skills taught in this manner can have excellent retention rates. Furthermore, an early focus on technical skills allows junior residents to perform at the same level as senior residents for certain tasks and may privilege later learning.

Simulation for Teaching Orthopaedic Residents in a Competency-based Curriculum: Do the Benefits Justify the Increased Costs?

BackgroundAlthough simulation-based training is becoming widespread in surgical education and research supports its use, one major limitation is cost. Until now, little has been published on the costs of simulation in residency training. At the University of Toronto, a novel competency-based curriculum in orthopaedic surgery has been implemented for training selected residents, which makes extensive use of simulation. Despite the benefits of this intensive approach to simulation, there is a need to consider its financial implications and demands on faculty time.Questions/purposesThis study presents a cost and faculty work-hours analysis of implementing simulation as a teaching and evaluation tool in the University of Toronto’s novel competency-based curriculum program compared with the historic costs of using simulation in the residency training program.MethodsAll invoices for simulation training were reviewed to determine the financial costs before and after implementation of the competency-based curriculum. Invoice items included costs for cadavers, artificial models, skills laboratory labor, associated materials, and standardized patients. Costs related to the surgical skills laboratory rental fees and orthopaedic implants were waived as a result of special arrangements with the skills laboratory and implant vendors. Although faculty time was not reimbursed, faculty hours dedicated to simulation were also evaluated. The academic year of 2008 to 2009 was chosen to represent an academic year that preceded the introduction of the competency-based curriculum. During this year, 12 residents used simulation for teaching. The academic year of 2010 to 2011 was chosen to represent an academic year when the competency-based curriculum training program was functioning parallel but separate from the regular stream of training. In this year, six residents used simulation for teaching and assessment. The academic year of 2012 to 2013 was chosen to represent an academic year when simulation was used equally among the competency-based curriculum and regular stream residents for teaching (60 residents) and among 14 competency-based curriculum residents and 21 regular stream residents for assessment.ResultsThe total costs of using simulation to teach and assess all residents in the competency-based curriculum and regular stream programs (academic year 2012–2013) (CDN 155,750, USD 158,050) were approximately 15 times higher than the cost of using simulation to teach residents before the implementation of the competency-based curriculum (academic year 2008–2009) (CDN 10,090, USD 11,140). The number of hours spent teaching and assessing trainees increased from 96 to 317 hours during this period, representing a threefold increase.ConclusionsAlthough the financial costs and time demands on faculty in running the simulation program in the new competency-based curriculum at the University of Toronto have been substantial, augmented learner and trainer satisfaction has been accompanied by direct evidence of improved and more efficient learning outcomes.Clinical RelevanceThe higher costs and demands on faculty time associated with implementing simulation for teaching and assessment must be considered when it is used to enhance surgical training.

A novel multimodal platform for assessing surgical technical skills

BACKGROUND Established methods for assessing surgical performance face limitations. Global rating scales and procedure-specific checklists are resource intensive and rely on expert opinions. Alternatives that use technology to track hand movements, such as magnetic and optical tracking systems, are generally expensive and ill suited to the surgical environment. METHODS The authors present a new platform that integrates a novel, low-cost optical tracking system, magnetic tracking technology and a videographic recording system to quantify surgical performance synchronously across all modalities. The validity of this platform was tested by examining its ability to differentiate between the performance of expert and novice participants on a basic surgical task. RESULTS Each modality was able to differentiate between expert and novice participants, and metrics were well correlated across modalities. CONCLUSIONS The authors have developed a platform for assessing surgical performance. It can operate in the absence of expert raters and has the potential to provide immediate feedback to trainees.