Correlation between perceptual, visuo-spatial, and psychomotor aptitude to duration of training required to reach performance goals on the MIST-VR surgical simulator.

Given the dynamic nature of modern surgical education, determining factors that may improve the efficiency of laparoscopic training is warranted. The objective of this study was to analyze whether perceptual, visuo-spatial, or psychomotor aptitude are related to the amount of training required to reach specific performance-based goals on a virtual reality surgical simulator. Sixteen MS4 medical students participated in an elective skills course intended to train laparoscopic skills. All were tested for perceptual, visuo-spatial, and psychomotor aptitude using previously validated psychological tests. Training involved as many instructor-guided 1-hour sessions as needed to reach performance goals on a custom designed MIST-VR manipulation-diathermy task (Mentice AB, Gothenberg, Sweden). Thirteen subjects reached performance goals by the end of the course. Two were excluded from analysis due to previous experience with the MIST-VR (total n = 11). Perceptual ability (r = -0.76, P = 0.007) and psychomotor skills (r = 0.62, P = 0.04) significantly correlated with the number of trials required. Visuo-spatial ability did not significantly correlate with training duration. The number of trials required to train subjects to performance goals on the MIST-VR manipulation diathermy task is significantly related to perceptual and psychomotor aptitude.

Discriminative validity of the Minimally Invasive Surgical Trainer in Virtual Reality (MIST-VR) using criteria levels based on expert performance.

BACKGROUND: Increasing constraints on the time and resources needed to train surgeons have led to a new emphasis on finding innovative ways to teach surgical skills outside the operating room. Virtual reality training has been proposed as a method to both instruct surgical students and evaluate the psychomotor components of minimally invasive surgery ex vivo. METHODS: The performance of 100 laparoscopic novices was compared to that of 12 experienced (>50 minimally invasive procedures) and 12 inexperienced (<10 minimally invasive procedures) laparoscopic surgeons. The values of the experienced surgeons' performance were used as benchmark comparators (or criterion measures). Each subject completed six tasks on the Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) three times. The outcome measures were time to complete the task, number of errors, economy of instrument movement, and economy of diathermy. RESULTS: After three trials, the mean performance of the medical students approached that of the experienced surgeons. However, 7-27% of the scores of the students fell more than two SD below the mean scores of the experienced surgeons (the criterion level). CONCLUSIONS: The MIST-VR system is capable of evaluating the psychomotor skills necessary in laparoscopic surgery and discriminating between experts and novices. Furthermore, although some novices improved their skills quickly, a subset had difficulty acquiring the psychomotor skills. The MIST-VR may be useful in identifying that subset of novices.

Visual and circadian responses to light in aged retinally degenerate mice.

The progression of photoreceptor degeneration in retinally degenerate (rd) mice commences early in postnatal development resulting in the complete loss of rods by 60-70 days of age followed by the more protracted loss of cones. We have previously shown that rd mice 80 days of age are capable of phase shifting their circadian locomotor rhythms in response to brief pulses of light and these animals show the same sensitivity as wild-type (+/+) controls. If surviving cones mediate these circadian responses, then one would expect the sensitivity of the circadian system in rd mice to decline with age and parallel the loss of cones. We demonstrate that aging rd mice (80-767 days of age) remain capable of photically regulating circadian locomotor rhythms in a manner indistinguishable from +/+ mice. Circadian responses to light do not parallel cone cell degeneration in rd mice. In contrast to the circadian responses to light, old (> 210 days of age) rd mice show no visually-evoked behavioral or electroretinogram (ERG) responses.