In a PBL environment, learning results from learners engaging in cognitive processes pivotal in the understanding or resolution of the problem. Using Tan's cognitive function disc, this study examines the learner's perceived cognitive functions at each stage of PBL, as facilitated by the PBL schema. The results suggest that these learners perceived themselves as employing certain cognitive functions, with each function specific to different PBL stages. The cognitive functions were (i) looking from different perspectives, (ii) generating many ideas, (iii) making connections, and (iv) synthesis. The identification of perceived dominant cognitive functions to the pedagogical stages of PBL can serve to advance classroom practices as it (i) provides a cognitive-centric approach to PBL, and (ii) allows the PBL schema to be used as a tool to scaffold cognitive functions.