%A Prof. Ignazio Licata %J Epistemologia XXXI (2008), pp. 177-192. %T Logical openness in Cognitive Models %X It is here proposed an analysis of symbolic and sub-symbolic models for studying cognitive processes, centered on emergence and logical openness notions. The Theory of logical openness connects the Physics of system/environment relationships to the system informational structure. In this theory, cognitive models can be ordered according to a hierarchy of complexity depending on their logical openness degree, and their descriptive limits are correlated to G?del-Turing Theorems on formal systems. The symbolic models with low logical openness describe cognition by means of semantics which fix the system/environment relationship (cognition in vitro), while the sub-symbolic ones with high logical openness tends to seize its evolutive dynamics (cognition in vivo). An observer is defined as a system with high logical openness. In conclusion, the characteristic processes of intrinsic emergence typical of ?bio-logic? - emerging of new codes-require an alternative model to Turing-computation, the natural or bio-morphic computation, whose essential features we are going here to outline. %D 2008 %K Simbolic and Sub-simbolic Cognitive Models; Information and System Theory; Emergence; Logical and Thermodynamical Openness ; Turing and Natural Computation %I Tilgher %L cogprints6638