Learning and distraction: Evidence for cognitive load interference in medical education.

backgroundDistraction may increase cognitive load. Cues may decrease it. But what happens if we cue in distracted learning environments? Does effective instruction buffer against the detrimental effects of distraction?

methodsIn a 2 × 2 factorial experiment, 117 s-year medical students without prior knowledge watched a standardised instructional video on abdominal ultrasound. Distraction was induced via a concurrent mental arithmetic task, and supportive cues were instructed via eye movement modelling examples of an expert's gaze. Image interpretation performance and cognitive load were measured before and after training.

resultsAs expected, cueing alone reduced extraneous cognitive load and improved learning. Distraction alone impaired learning. However, when both interventions were combined, the performance benefits of cueing disappeared. Distracted learners receiving cues performed no better than uncued distracted learners, indicating no compensatory effect. Thus, distraction not only weakened learning but blocked the effectiveness of instructional benefits.

conclusionsThe disappearance of instructional benefits under distraction suggests a load interference mechanism: Learners cannot benefit from helpful educational instructions when their working memory is already taxed by competing demands. Importantly, this blocking effect represents more than a simple additive effect-it demonstrates a qualitative breakdown where helpful instructional elements become ineffective rather than merely weakened. We discuss the implications for medical education in increasingly distraction-rich learning environments characterised by AI, smartphone notifications and electronic health record alerts.