There has been much discussion recently about the scope and limits of purely symbolic models of the mind and about the proper role of connectionism in cognitive modeling. This paper describes the "symbol grounding problem": How can the semantic interpretation of a formal symbol system be made intrinsic to the system, rather than just parasitic on the meanings in our heads? How can the meanings of the meaningless symbol tokens, manipulated solely on the basis of their (arbitrary) shapes, be grounded in anything but other meaningless symbols? The problem is analogous to trying to learn Chinese from a Chinese/Chinese dictionary alone. A candidate solution is sketched: Symbolic representations must be grounded bottom-up in nonsymbolic representations of two kinds: (1) "iconic representations" , which are analogs of the proximal sensory projections of distal objects and events, and (2) "categorical representations" , which are learned and innate feature-detectors that pick out the invariant features of object and event categories from their sensory projections. Elementary symbols are the names of these object and event categories, assigned on the basis of their (nonsymbolic) categorical representations. Higher-order (3) "symbolic representations" , grounded in these elementary symbols, consist of symbol strings describing category membership relations (e.g., "An X is a Y that is Z"). Connectionism is one natural candidate for the mechanism that learns the invariant features underlying categorical representations, thereby connecting names to the proximal projections of the distal objects they stand for. In this way connectionism can be seen as a complementary component in a hybrid nonsymbolic/symbolic model of the mind, rather than a rival to purely symbolic modeling. Such ...

Pinker, S. & Bloom, P. (1990). Natural language and natural selection. Behavioral and Brain Sciences 13

Abstract not found

We report a new phenomenon associated with language comprehension: the action–sentence compatibility effect (ACE). Participants judged whether sentences were sensible by making a response that required moving toward or away from their bodies. When a sentence implied action in one direction (e.g., “Close the drawer ” implies action away from the body), the participants had difficulty making a sensibility judgment requiring a response in the opposite direction. The ACE was demonstrated for three sentences types: imperative sentences, sentences describing the transfer of concrete objects, and sentences describing the transfer of abstract entities, such as “Liz told you the story. ” These data are inconsistent with theories of language comprehension in which meaning is represented as a set of relations among nodes. Instead, the data support an embodied theory of meaning that relates the meaning of sentences to human action. How language conveys meaning remains an open question. The dominant approach is to treat language as a symbol manipulation system: Language conveys meaning by using abstract, amodal, and arbitrary symbols (i.e., words) combined by syntactic rules (e.g., Burgess & Lund, 1997; Chomsky, 1980; Fodor, 2000; Kintsch, 1988; Pinker, 1994). Words are abstract in that the same word, such as “chair, ” is used for big chairs and little chairs, words are amodal in that the same word is used when chairs are spoken about or written about, and words are arbitrarily related to their referents in that the phonemic and orthographic characteristics of a word bear no relationship to the physical or functional characteristics of the word’s referent. An alternative view is that linguistic meaning is

Quartz, S. & Sejnowski, T.J. (1997). The neural basis of cognitive development: A constructivist manifesto.

This paper applies another mechanism than genetic evolution for structure formation to the problem of language formation, namely self-organisation. Self-organisation occurs in complex dynamical systems which are coupled in a particular way. Standard examples are the formation of a termite nest [2] or a path in an ant society. This paper focuses on the formation of vocabularies, i.e. a set of couplings between words and meanings. A common vocabulary will be viewed as a selforganising phenomenon similar to a path in an ant society. Each agent is assumed to create his own vocabulary in a random fashion. But agents are coupled because they must share vocabularies in order to obtain the benefit of cooperating through communication. Agents therefore keep changing their own private vocabulary until it is conform to the common vocabulary. It will be shown that under certain conditions a coherent but still evolving vocabulary emerges. The rest of the paper is in three parts. The first section introduces the kernel mechanism responsible for self-organisation. The second section introduces a spatio-temporal dynamics which ensures that the kernel mechanism copes with combinatorial explosions. The final section reports the results of some simulation experiments. 2 The self-organising kernel

Many theorists have dismissed a priori the idea that distributional information could play a significant role in syntactic category acquisition. We demonstrate empirically that such information provides a powerful cue to syntactic category membership, which can be exploited by a variety of simple, psychologically plausible mechanisms. We present a range of results using a large corpus of child-directed speech and explore their psychological implications. While our results show that a considerable amount of information concerning the syntac-tic categories can be obtained from distributional information alone, we stress that many other sources of information may also be potential contributors to the identification of syntactic classes. I.

Language is a shared set of conventions for mapping meanings to expressions. This paper explores self-organization as the primary mechanism for the formation of a vocabulary. It reports on a computational experiment in which a group of distributed agents develop ways to identify each other using names or spatial descriptions. It is also shown that the proposed mechanism copes with the acquisition of an existing vocabulary by new agents entering the community and with the expansion of the set of meanings. 1 Introduction How did language originate and how are agents capable to acquire the existing language of their community? Various theories have been offered in the linguistic and cognitive science literature. One theory, proposed and defended by Chomsky and his school, states that grammar is innate [1]. More precisely, there is an innate language acquisition device based on a universal grammar so that the acquisition of a new language is a matter of setting switches (choosing paramete...

The paper reports on experiments in which robotic agents and software agents are set up to originate language and meaning. The experiments test the hypothesis that mechanisms for generating complexity commonly found in biosystems, in particular self-organisation, co-evolution, and level formation, also may explain the spontaneous formation, adaptation, and growth in complexity of language.

The paper reports experiments to test the hypothesis that language is an autonomous evolving adaptive system maintained by a group of distributed agents without central control. The experiments show how a coherent lexicon may spontaneously emerge in a group of agents engaged in language games and how a lexicon may adapt to cope with new meanings that arise or new agents that enter the group. The lexicon has several characteristics of natural language lexicons, such as polysemy, synonymy and ambiguity. Keywords: origins of language, lexicon acquisition, self-organization. 1 Introduction The origins and evolution of language is still clouded in mystery, despite an extensive literature within linguistics, psychology, anthropology and neurobiology (see a recent overview in [15]). The most common hypothesis being explored in American linguistics is that language is based on a species-specific innate ability (a kind of language organ) and on the refinement of innate knowledge (universal gr...