Computational Models of Language Toward Brain-Style Computing

Abstract

The human brain consists of a neural system as hardware and a language system as software. It is, therefore, possible to take two approaches to create the human brain. While the hardware-centered approach is based on computational neuroscience, it is possible to base the software-centered approach on linguistics. Brain-style computing is considered as one of the main research areas in creating the brain. We take a language-based approach to brain-style computing. To this aim, we have adopted as the basic theory Systemic Functional Linguistics (SFL) initiated by Halliday. Following Halliday's four principles in the design of human language, we have implemented the computational model of language in context, called the Semiotic Base, and we have developed a set of algorithms of text understanding and generation using this model. The language used in this study is Japanese. As an application of the models, we are developing Brain-Style Computing System under which we can manage and execute all kinds of computing through meanings. The idea is to verbalize computers by constructing linguistic models of software and hardware applications. Brain-Style Computing System consists of Everyday Language Interface with a Secretary Agent, Semiotic Base, Language Applications, Language Communication Protocol and Language Operating System. In this talk, I shall discuss some linguistic issues in creating the brain. There are three higher-order functions of the brain concerned with language: processing, utilizing, and learning language. Processing language such as understanding and generation is a basic function with the internal models of language itself and its processing. SFL could reveal what the internal models must be like. SFL could also play an essential role in elucidating the brain functions of language such as thinking with language and learning language. I shall also show some clinical evidence obtained from studies on aphasia which support the SFL perspective on the system of language. I shall also refer to the brain internal models for motor control and some learning mechanisms in the brain which might be related with language functions.