Experience Reflected in Eye Movement
Orange County, CA - July 18th 2016 - Can competency be measured in eye movement? A study from Finland seems to think so. Raymond Bertram, MS, PhD led a team of researchers at Helsinki University Hospital and Turku University Central Hospital to find inconsistencies in how radiologists at various levels of their career see medical images.
Researchers used 26 abdominal CT studies to test the visual acuity of 41 radiologists comprised of early residents (1.5 years or less experience), advanced residents (1.5 – 3.5 years of experience), and specialists (up to 22 years of experience in abdominal radiology).
Using a desktop eye tracker, researchers collected data by monitoring eye movement from each radiologist as they studied the set of CT scans, distributed at either three or five frames per second. The researchers then applied a linear mixed-effects model to the eye movement data they collected, giving them the ability to study correlations amongst the radiologists.
The researchers captured the duration of fixation and saccades, two aspects of visual information absorption produced by eye movement. While fixation refers to gazing at a single location for a prolonged a period of time, saccades are rapid eye movements that occur during fixation.
Findings show that the duration of fixation increases with presentation speed in specialists and residents, but not early residents, proving the existence of an apparent disparity in eye movement patterns based on level of experience.
Measuring the length of saccades to convey level of expertise was especially telling with images of lesions, as it’s believed that visual information cannot be apprehended during this type of rapid eye movement. While viewing scans, the specialists were noted to have shorter spans of saccades, which is indicative of increased rate of information retention.
Regardless of training, however, researchers found a correlation in shorter saccade length with a high detection rate in the presence of lesions and faster presentation frames. Furthermore, early residents exhibited impediments in identifying low visual contrast lesions compared to their advanced counterparts.
In addition, the least experienced subset of radiologists showed a marked drop in lesion detection as the day progressed, denotative of their unconversant eyes. In contrariety, advanced residents and specialists possessed longer fixation periods at 5 than at 3 frames per second.
The study’s findings suggest a new methodology for assessing and analyzing level of radiological astuteness. Adopting a similar measurement tool can help residents determine potential shortcomings when reading results and inform scheduling, for there is a higher rate of exhaustion in new residents exhaustion than advanced residents and specialists.
“The analysis of expertise development by eye-movement behavior could be useful in monitoring individual residents’ learning curves and contribute to a shift toward competency-based resident training,” the researchers said.
