In 1982 Teuvo Kohonen proposed an algorithm called Self Organizing Map (SOM) that is basically a stochastic model of the establishment of topology preserving connections between the retina and the cortex in our brain. That model has proved an efficient classification tool, a source of inspiration for other biological models and also for the understanding of the principles of self-organization. In this paper, we present a modification of the initial SOM to address an important problem in semantic cognition: the representation of human concepts in the brain. Much of the knowledge acquired in the last decades in this field comes from the study of patients with acquired difficulties in language. The modification presented here is inspired in semantic dementia, a devastating pathology that introduces the deterioration of semantic knowledge into the brain. The paper discusses the model and describes some preliminary results that show its interest as the basis of possible new tools to help to understand the considered type of diseases.