[Functional contribution of the parafascicular complex of the thalamus to complex forms of behavior in cats].

The role of the thalamic parafascicular complex in cognitive processes was studied in free behaviour of cats on an original model of alternative choice with generalization of different signals systems by the principle of formation of preverbal concept "more-less". It is shown that the lateral part of the complex is involved in the mechanisms of generalization and abstraction, and the medial one--in conditioned activity. Biological bases of thalamic dementia are discussed.