Recognizing variable spatial environments--The theory of cognitive prism

Abstract

Objects are not statically located in environments. Therefore, a snapshot view of an environment at one moment may be quite different from its snapshot at other moments. However, people are capable of recognizing the environment. This thesis presents a theory of recognizing variable spatial environments -- The Theory of Cognitive Prism. It collected theoretical and empirical evidences from several disciplines, such as cognitive psychology, neurology, psycho-linguistics, philosophy, and proposes a symbolic computational theory. This thesis has three parts: The first part is the description of the theory in natural language. It presents a commonsense knowledge of the snapshot view of a spatial environment -- the "cognitive spectrum", and of the process of recognizing a spatial environment by comparing two cognitive spectrums. The second part is the mereotopological formalism of the theory. It presents the formal structure of the cognitive spectrum and the process of comparing two formalized cognitive spectrums. The third part introduces a symbolic simulating system of the theory -- the LIVE model.The research questions are: (1) What are the spatial relations between extended objects through observation? (2) According to what principle is the reference orderingbetween extended objects formed? (3) What is the structure of a cognitive spectrum? (4) How shall two cognitive spectrums be compared? (5) How does the differencebetween two cognitive spectrums determine the degree of the compatibility between the perceived cognitive spectrum and the target one? (6) How shall the results of Question (1) to (5) be formalized? Distance relations between extended objects are understood by the degree of the extension from one extended object to the other; orientation relations between two extendedobjects are distance comparison between one extended object and sides of the other extended object. The reference ordering between two extended objects is based on the commonsense knowledge of relative stabilities of related objects. The cognitive spectrum is structured by extended objects and their spatial relations which obey the reference ordering. Two cognitive spectrums are compared based on the categories and locations of extended objects. The compatibility of two cognitive spectrums is determined by their differences and relative stabilities of related objects. Recognizing spatial environments is the comparison process between the cognitive spectrum of the perceived environment and the cognitive spectrum of target environment and the judgement of the compatibility between them. All above are mereotopolgically formalized by the connectedness relationship C. The computational complexity of the formalized recognition process is polynomial P. A symbolic simulation system, the LIVE model, has been implemented in Lisp.