A Tsallis’ statistics based neural network model for novel word learning

• Published in: Physica A Vol. 388; no. 5; pp. 732 - 746
• Main Authors: Hadzibeganovic, Tarik, Cannas, Sergio A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2009
• Subjects: Nonextensive statistical mechanics; Novel word learning; Perceptron; Tsallis entropy; 05.10.-a; 87.19.lj; Perceptron; 43.71.Hw; 87.19.lv; Tsallis entropy; Novel word learning; Nonextensive statistical mechanics
• ISSN: 0378-4371; 1873-2119
• DOI: 10.1016/j.physa.2008.10.042

We invoke the Tsallis entropy formalism, a nonextensive entropy measure, to include some degree of non-locality in a neural network that is used for simulation of novel word learning in adults. A generalization of the gradient descent dynamics, realized via nonextensive cost functions, is used as a learning rule in a simple perceptron. The model is first investigated for general properties, and then tested against the empirical data, gathered from simple memorization experiments involving two populations of linguistically different subjects. Numerical solutions of the model equations corresponded to the measured performance states of human learners. In particular, we found that the memorization tasks were executed with rather small but population-specific amounts of nonextensivity, quantified by the entropic index q. Our findings raise the possibility of using entropic nonextensivity as a means of characterizing the degree of complexity of learning in both natural and artificial systems.