Activating student knowledge (ASK) before receiving learning materials improves their learning outcome (Tormey and LeDuc (2014)). We implement ASK through priming by using two versions of the same pretest in a dual eye-tracking study in a MOOC context. We propose an additional activity, a collaborative concept-map, based on the MOOC lecture to enable the students to reflect on what they learnt. The priming affects the learning gain, individual and collaborative gaze patterns. Textual priming stands better than schema priming in terms of learning outcome. Finally, the pairs having participants with similar gaze to each other have more learning gain.