Explanation: While studying for the neuroscience test, Houda listened to music she chose, that is, which she loves, which relaxes her, stimulates her, and so on. She probably didn't like the subject of neuroscience initially as the music she loves and listens to, but it's something that must be done, not initially loved. Her nodding to the rhythm of the music meant approval for the music she was listening to, which she transferred over time to the learning subject, that is, she linked that approval to the subject.