Visual working memory influences the performance in virtual image-guided surgical intervention

Background: This study addresses for the first time the relationship between working memory and performance measures in image-guided instrument navigation with Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) and GI Mentor II (a simulator for gastroendoscopy). In light of recent research on simulator training, it is now prime time to ask why in a search for mechanisms rather than show repeatedly that conventional curriculum for simulation training has effect. Methods: The participants in this study were 28 Swedish medical students taking their course in basic surgery. Visual and verbal working memory span scores were assessed by a validated computer program (RoboMemo) and correlated with visual-spatial ability (MRTA test), total flow experience (flow scale), mental strain (Borg scale), and performance scores in manipulation and diathermy (MD) using Procedicus MIST-VR and GI Mentor II (exercises I and 3). Results: Significant Pearson's r correlations were obtained between visual working memory span scores for visual data link (a RoboMemo exercise) and movement economy (r = -0.417; p < 0.05), total time (r = -0.495; p < 0.01), and total score (r = -0.390; p < 0.05) using MIST-MD, as well as total time (r = -0.493; p < 0.05) and efficiency of screening (r = 0.469; p < 0.05) using GI Mentor II (exercise 1). Correlations also were found between visual working memory span scores in rotating data link (another RoboMemo exercise) and both total time (r = -0.467; p < 0.05) and efficiency of screening (r = -0.436; p < 0.05) using GI Mentor 11 (exercise 3). Significant Pearson's r correlations also were found between visualspatial ability scores and several performance scores for the MIST and GI Mentor II exercises. Conclusions: Findings for the first time demonstrate that visual working memory for surgical novices may be important for performance in virtual simulator training with two well-known and validated simulators.