This empirical study reports an intervention to investigate identified research challenges on the evaluation and use of ambient displays in a learning context with the objective to gain insights into the interplay between display design, user attention, and knowledge acquisition. The main research questions were whether an attention-aware display design can capture the user's focus of attention and whether this has an influence on the knowledge gain. A display prototype corresponding to the main ambient display characteristics was designed, applied in a controlled authentic setting, and evaluated accordingly. The prototype presented information and guidelines for first responders in emergency situations, especially in cases of cardiac arrest. The prototype was enhanced with a custom-built sensor to measure user attention and trigger interruptive notifications. The study was conducted among 52 employees working at a university campus. Using an experimental research design, a treatment group exposed to an attentionaware display design was compared to a control group. The results provide evidence that such a display design can attract and retain attention in such a way that the acquisition of knowledge (i.e. the comprehension of the presented information) is effectively facilitated.