Language Evolution and Computation Bibliography

The advent of humanoid robots has enabled a new approach to investigating the acquisition of language, and we report on the development of robots able to acquire rudimentary linguistic skills. Our work focuses on early stages analogous to some characteristics of a human child of about 6 to 14 months, the transition from babbling to first word forms. We investigate one mechanism among many that may contribute to this process, a key factor being the sensitivity of learners to the statistical distribution of linguistic elements. As well as being necessary for learning word meanings, the acquisition of anchor word forms facilitates the segmentation of an acoustic stream through other mechanisms. In our experiments some salient one-syllable word forms are learnt by a humanoid robot in real-time interactions with naive participants. Words emerge from random syllabic babble through a learning process based on a dialogue between the robot and the human participant, whose speech is perceived by the robot as a stream of phonemes. Numerous ways of representing the speech as syllabic segments are possible. Furthermore, the pronunciation of many words in spontaneous speech is variable. However, in line with research elsewhere, we observe that salient content words are more likely than function words to have consistent canonical representations; thus their relative frequency increases, as does their influence on the learner. Variable pronunciation may contribute to early word form acquisition. The importance of contingent interaction in real-time between teacher and learner is reflected by a reinforcement process, with variable success. The examination of individual cases may be more informative than group results. Nevertheless, word forms are usually produced by the robot after a few minutes of dialogue, employing a simple, real-time, frequency dependent mechanism. This work shows the potential of human-robot interaction systems in studies of the dynamics of early language acquisition.

This volume brings together studies from diverse disciplines, showing how they can inform and stimulate each other. It includes work in linguistics, psychology, neuroscience, anthropology and computer science. New empirical work is reported on both human and animal communication, using some novel techniques that have only recently become workable.

A principal theme is the importance of studies involving artificial agents, their contribution to the body of knowledge on the emergence of communication and language, and the role of simulations in exploring some of the most significant issues. A number of different synthetic systems are described, showing how communication can emerge in natural and artificial organisms. Theories on the origins of language are supported by computational and robotic experiments.

Worldwide contributors to this volume include some of the most influential figures in the field, delivering essential reading for researchers and graduates in the area, as well as providing fascinating insights for a wider readership.

Contents

Introduction

Current Work and Open Problems: A Roadmap for Research into the Emergence of Communication and Language by Chrystopher L. Nehaniv, Caroline Lyon, and Angelo Cangelosi

Section 1: Empirical Investigations on Human Language

• Evolving Meaning: The Roles of Kin Selection, Allomothering and Paternal Care in Language Evolution by W. Tecumseh Fitch
• `Needs only' Analysis in Linguistic Ontogeny and Phylogeny by Alison Wray
• Clues from Information Theory Indicating a Phased Emergence of Grammar by Caroline Lyon, Chrystopher L. Nehaniv and Bob Dickerson
• Emergence of a Communication System: International Sign by Rachel Rosenstock
• Distributed Language: Biomechanics, Functions, and the Origins of Talk by Stephen J. Cowley

Section 2: Synthesis of Communication and Language in Artificial Systems

• The Recruitment Theory of Language Origins by Luc Steels
• In silico Evolutionary Developmental Neurobiology and the Origin of Natural Language by Eors Szathmary, Zoltan Szatmary, Peter Ittzes, Gergo Orban, Istvan Zachar, Ferenc Huszar, Anna Fedor, Mate Varga, Szabolcs Szamado
• Communication in Natural and Artificial Organisms: Experiments in Evolutionary Robotics by Davide Marocco and Stefano Nolfi
• From Vocal Replication to Shared Combinatorial Speech Codes: A Small Step for Evolution, a Big Step for Language by Pierre-Yves Oudeyer
• Learning and Transition of Symbols: Towards a Dynamical Model of a Symbolic Individual by Takashi Hashimoto and Akira Masumi
• Language Change among `Memoryless Learners' Simulated in Language Dynamics Equations by Makoto Nakamura, Takashi Hashimoto and Satoshi Tojo
• The Evolution of Meaning-space Structure through Iterated Learning by Simon Kirby
• The Emergence of Language: How to Simulate It by Domenico Parisi and Marco Mirolli
• Lexical Acquisition with and without Metacommunication by Jonathan Ginzburg and Zoran Macura
• Agent Based Modelling of Communication Costs: Why Information Can be Free by Ivana Cace and Joanna Bryson
• Language Change and the Inference of Meaning by Andrew D. M. Smith
• Language, Perceptual Categories and their Interaction: Insights from Computational Modelling by Tony Belpaeme and Joris Bleys

Section 3: Insights from Animal Communication

• Emergence of Linguistic Communication: Studies on Grey Parrots by Irene M. Pepperberg
• A Possible Role for Selective Masking in the Evolution of Complex, Learned Communication Systems by Graham R. S. Ritchie and Simon Kirby
• The Natural History of Human Language: Bridging the Gaps without Magic by Bjorn Merker and Kazuo Okanoya
• Neural Substrates for String-Context Mutual Segmentation: A Path to Human Language by Kazuo Okanoya and Bjorn Merker

The original idea for this book came from the successful 2nd International Symposium on the Emergence and Evolution of Linguistic Communication (EELC '05) held in Hatfield, UK, in April 2005. Grants from the British Academy and the UK Engineering and Physical Sciences Research Council in support of this workshop are gratefully acknowledged.

We examine evidence for the hypothesis that language could have passed through a stage when words were combined in structured linear segments and these linear segments could later have become the building blocks for a full hierarchical grammar. Experiments were carried out on the British National Corpus, consisting of about 100 million words of text from different domains and transcribed speech. This work extends and supports the results of our previous work based on a smaller corpus reported previously. Measuring the entropy of the texts we find that entropy declines as words are taken in groups of 2, 3 and 4, indicating that it is easier to decode words taken in short sequences rather than individually. Entropy further declines when punctuation is represented, showing that appropriate segmentation captures some of the language structure. Further support for the hypothesis that local sequential processing underlies the production and perception of speech comes from neurobiological evidence. The observation that homophones are apparently ubiquitous and used without confusion also suggests that language processing may be largely based on local context.