Analyse visuelle et cérébrale de l’état cognitif d’un apprenant

A cognitive state can be defined as a set of inferior (e.g. perception and attention) and superior (e.g. perception and attention) cognitive processes, requiring the human being to have all of his  mental abilities in an effort to use existing knowledge to solve a given problem or to establish new knowledge. In this context, a particular attention is paid by computer-based learning environments to monitor and assess learner’s emotional reactions during a learning activity. In fact, emotions govern the learner’s mental state that has in turn a direct impact on his cognitive abilities such as reasoning, decision-making, memory, etc. In this context, the objective is to improve the cognitive abilities of the learner by identifying and redressing the mental states that are unfavorable to learning in order to optimize the learners’ performances. In this thesis, we aim in particular to examine the reasoning as a high-level cognitive process. Our goal is two-fold: first, we seek to evaluate the reasoning process of novice medical students through their visual behavior and second, we seek to analyze learners’ mental states when reasoning to detect visual and cerebral indicators that can improve learning outcomes. More specifically, our first objective was to use the learner’s eye movements to assess his reasoning process while interacting with educational serious games. For this purpose, we have analyzed two types of ocular metrics namely, static metrics and dynamic metrics. First of all, we have studied the feasibility of using static metrics to automatically identify two groups of learners through the training of machine learning algorithms. Then, we have assessed the logical visual sequence followed by the learner when reasoning using dynamic metrics and a sequence alignment method from bio-informatics to see if he/she performed the correct reasoning process or not.  Our second objective was to analyze the evolution of the learner’s engagement mental state from his brain activity and to assess the relationship between engagement and learning performance. An experimental study was conducted where we analyzed the distribution of the learner engagement index through first, the different phases of the problem-solving task and second, through the different regions of the environment interface. The cerebral activity of each participant was recorded during the whole game interaction. Then, from the obtained signals, an engagement index was computed based on the three frequency bands α, β et θ. Finally, our third objective was to propose a multimodal approach based on two physiological sensors to provide a joint analysis of the learner’s visual and cerebral behaviors. To this end, we recorded eye movements and brain activity of the learner to assess his reasoning process during the resolution of different cognitive tasks. More precisely, we aimed to identify key indicators of reasoning performance in order to use them to improve the cognitive abilities of novice learners in particular, and the learning experience in general.

Keyphrases: Eye movements, Cerebral activity, Visual behavior, Emotions, Reasoning process, Learner’s mental state analysis, Serious games, Learning performance assessment, Sequence alignment