Based on the established framework of Cognitive Load Theory, the presented research focuses on the inspection of cognitive load factors in an interrupted learning task. The task itself is inspired from basic cognitive research and demands participants to learn abstract symbol sequences of varying complexity. In addition, they have to deal with interruptions while performing the task. Experimental results indicate the influence of task complexity on how interruptions effect learning performance. However, questions on underlying learner cognition persist, rising the need for a more in-depth way of examination. For this purpose, a cognitive model within the cognitive architecture ACT-R is developed to clarify cognitive processes and mechanisms within different conditions of the task. Preliminary results from a first model for the easy task condition already indicate some fit between human and model data. Modeling work continues with adjusting the current model and implementing a model for the difficult task condition.