On the Effect of Laser Projection Operator Guidance on Cognitive Workload and Task Performance

This study examines three instructional modalities—laser projection, video, and pictorial guidance—in a VR-based manufacturing assembly task. Twenty-five participants ( M = 24.5 years) completed a 20-block layout task under easy (no-task) and hard (1-back) conditions. Cognitive workload (ocular metrics, NASA-TLX) and task performance (completion time, accuracy) were measured. Laser projection showed the lowest blink rate ( M = 14.7 blinks/min) and fastest times ( M = 241 s) versus video ( M = 18.6 blinks/min, M = 353 s) and pictorial ( M = 22.2 blinks/min, M = 276 s), suggesting less cognitive strain. Pupil dilation was higher for laser ( M = 2.82) and video ( M = 2.96) than pictorial ( M = 2.28), likely due to VR light reflexes. Accuracy was similar across modalities. Hard conditions increased workload, reducing performance. Laser projection enhances efficiency for complex assemblies, with implications for smart manufacturing.