Cognitive Mechanisms in Drone Delivery Interaction Interfaces: An Eye-Tracking Study

As drone delivery expands into dense, dynamic, and cognitively demanding low-altitude environments, the design of ground-station interaction interfaces has become increasingly critical to operational safety, efficiency, and situation awareness. Existing studies on unmanned aerial vehicle (UAV) operation have emphasized global task performance and workload outcomes, yet have paid insufficient attention to the cognitive processing mechanisms through which interface design influences operator behavior. In particular, limited empirical evidence is available on how interface pop-up strategy, training intervention, and task difficulty jointly shape attention allocation and visual search in drone delivery contexts. To address this gap, this study investigates the cognitive mechanisms of drone delivery interaction interfaces by comparing two pop-up strategies, immediate-triggering and continuous-display, while further examining the roles of short-term training and progressive task difficulty. A 2 (training group: trained vs. untrained) × 2 (pop-up type: immediate-triggering vs. continuous-display) × 4 (task difficulty) mixed experimental design was adopted. Forty participants were recruited, and 32 valid samples were retained after data cleaning. Using the DJI flight simulator as the experimental platform, the study synchronously collected behavioral performance, subjective cognitive load, and eye-tracking data. Eye-tracking indicators included total fixation duration, time to first fixation (TTFF), total saccade amplitude, average pupil diameter (APD), and fixation proportion in the main information area, in order to capture operators’ cognitive resource allocation, attentional orientation, and visual search organization during task execution. The results showed that task difficulty was the dominant factor affecting behavioral performance. Task completion time increased significantly across task units, confirming the validity of the difficulty gradient. Although repeated task execution produced a practice effect, this effect weakened and tended to disappear under the highest-difficulty condition, suggesting that behavioral benefits from repeated exposure were constrained by task complexity. In contrast, neither short-term training nor pop-up type produced significant advantages in overall behavioral efficiency or global subjective workload, indicating that the effects of interface optimization cannot be adequately captured by macroscopic performance indicators alone. More importantly, the eye-tracking results revealed differentiated cognitive processing patterns that were not reflected in behavioral outcomes. Compared with the continuous-display condition, the immediate-triggering condition was associated with shorter TTFF, indicating faster orientation to critical information. By contrast, the continuous-display condition showed relatively longer fixation duration and a more distributed scanning pattern, suggesting a different visual search organization strategy. In addition, total saccade amplitude changed significantly across task progression, indicating that increasing task difficulty primarily expanded the scope of visual search, whereas its effect on initial attentional orientation was more limited. The fixation proportion in the main view area also generally increased with task difficulty, suggesting that operators increasingly concentrated attentional resources on core flight information under high-load conditions. Regarding training effects, short-term training did not directly translate into a stable behavioral advantage, but trend-level differences in attentional stability emerged under high-difficulty tasks. In particular, trained participants, especially under the continuous-display condition, showed relatively more stable attentional allocation at the most demanding stage, suggesting that the value of training may lie more in supporting cognitive organization and attentional stability than in directly improving overt performance within a short intervention period. Exploratory analyses further suggested that gender may be associated with differentiated eye-movement response patterns and interface adaptation strategies, although these findings require verification with larger samples. Overall, this study shows that the optimization value of drone delivery interfaces lies not only in improving task completion efficiency, but more importantly in shaping cognitive processing pathways, regulating attentional resources, and supporting situation awareness under increasing task demands. By combining behavioral, subjective, and eye-tracking evidence, the study offers a process-oriented human factors perspective for evaluating UAV interaction interfaces and provides empirical support for the design of cognitively adaptive interface strategies in complex low-altitude delivery scenarios.