The aim of this paper is to show how an innovative technique can be used to introduce a method for uncovering intrinsic mechanisms that motivate changes in students' mental models. The theoretical framework used to develop the method is based on the ONEPSY (ONtology, EPistemology and PSYchology) model. The ONEPSY model is rooted in the theoretical constructs of cognitive psychology (Johnson-Laird) and artificial intelligence on mechanistic mental models (de Kleer and Brown) as well as the psychological theories developed by Piaget and others about the construction of knowledge and cognitive mechanisms that enable us to learn and survive in the world. This method was used when regulating a dialogue between a teacher (interviewer) and a student (interviewee) and also when analysing this dialogue subsequently. Pask's "teachback" technique was used to regulate the interview and showed its effectiveness for helping a student both to identify his difficulties and to be able to overcome them; it also helped him to develop the ability to build models that gradually move closer to scientific models based on intuitive reasoning (mental models). The emotions experienced by students during this process have been shown to be a decisive driving force--intrinsic motivation--for constructing and reconstructing their intuitive models and acquiring increasingly satisfactory mental models. The different regulatory processes controlled by the interviewer during the dialogue have also been outlined.