Interest is a critical motivational factor in education, and a vast number of empirical studies in psychology have revealed the beneficial effects of interest on learning outcomes. Despite the many different theoretical perspectives on interest, however, previous studies hold a common assumption that interest promotes learning by increasing positive motivational commitment to a task (i.e., motivational benefit of interest). Going beyond this assumption, the current project points to the possibility that there is another hidden, non-motivational benefit of interest on learning, and proposes the novel hypothesis that interest can directly consolidate learning without being mediated by any motivational or attentional processes. The proposal will examine this direct consolidation hypothesis of interest using a multidisciplinary approach, combining behavioural, neurological, and metacognitive perspectives. Study 1 will behaviourally test the direct consolidation hypothesis using a new methodology: post-encoding motivation manipulation. I expect that interesting events will enhance long-term learning, even for the interest-irrelevant materials that are presented prior to the interesting event. Study 2 will use functional magnetic resonance imaging to test the hypothesis that the non-motivational effect of interest on learning is produced by the direct modulation of striatal reward system in the hippocampal memory system. Study 3 will examine the metacognitive consequences of the direct consolidation of interest. Specifically, I will investigate the possibility that the unawareness of the non-motivational benefit of interest will produce underconfidence (as opposed to the overconfidence that past literature has commonly observed) and, therefore, maladaptive self-regulated study of interesting materials. These findings will not only open a new avenue for future research on interest, but also suggest practical implications for educational programs to promote interest.