Teaching is ineffective when students are distracted: Cognitive load interference in medical education

Abstract Background Distraction impairs attention—a growing concern in medical training, where students face constant digital alerts and multitasking demands. While teaching strategies, such as cueing, have proven effective under optimal conditions, their performance under cognitive overload remains unexplored. This raises the question: Can effective instruction buffer against the detrimental effects of distraction? Methods In a 2x2 factorial experiment, 117 second-year medical students without prior knowledge watched a standardized instructional video on abdominal ultrasound. Distraction was induced via concurrent mental arithmetic task, and cues were provided via eye movement modeling examples of an expert’s gaze. Image interpretation performance as a primary outcome and cognitive load were measured before, and after training. Results As expected, cueing alone reduced extraneous cognitive load and improved learning. Distraction alone impaired learning. However, when both were combined, the performance benefits of cueing disappeared. Distracted learners receiving cues performed no better than uncued distracted learners, indicating no compensatory effect. Conclusions The disappearance of cueing benefits under distraction suggests a load interference mechanism: learners cannot benefit from helpful educational instructions when their cognitive capacity is already taxed by competing demands. This indicates that internal distraction effectively monopolizes limited working memory resources of students. We discuss the implications for medical education in increasingly distraction-rich learning environments characterized by social media, smartphone notifications, and electronic health record alerts.