Accounts of students' learning have increasingly emphasised the role of affective engagement in achievement settings. Although most studies have focused on negative emotional experiences such as anxiety, more recent studies have investigated the role of positive emotions. This study examines the structure of students' subjective learning experiences in relation to individual interest profiles. It measured two components of affect: activation as positive arousal that indicates engagement, and valence as an evaluative quality of the students' experience. Senior secondary students (females, N=162) completed measures of individual interests, curiosity and prior knowledge, read three social issues texts and then answered some questions relating to the texts. Each text was divided into three sections and at the end of each section students completed separate activation and valence measures. Three individual interest profiles were generated using cluster analysis, and dynamic patterns of activation were tracked for each group. Findings using individual interest profiles illustrate the interactive engagement processes between students and specific tasks. Additionally, students reported a wide range of emotions, both positive and negative, indicating the broad and content-specific nature of students' emotional experiences while engaged in academic tasks.