UNIVERSITY OF HERTFORDSHIRE
     
         COMPUTER SCIENCE RESEARCH COLLOQUIUM


                     presents




    ``The Value of Segmentation of Speech in the 

           Evolution of Language Structure 

 (Or: Survival of the Fittest in the Statistical Environment)''



                        by 

                Dr. Caroline Lyon
            (University of Hertfordshire)



            20 February 2002 (Wednesday)

               Lecture Theatre LC108
                     3 - 4 pm 


      Coffee/tea and biscuits will be available.


            EVERYONE IS WELCOME TO ATTEND!




Abstract:

Consider a scenario in the distant past, where two tribes are planning to
catch some deer. Suppose the leader of one tribe can say things like:
"Hide in the tree where I waited with your father while I chase the deer
past you down the gully". Compare this to the utterance of the leader of
another tribe who can only string words together in an unstructured way:
"Hide tree wait father chase deer gully". An advantage is conferred  by
the ability to use structured language.

This seminar shows why a necessary intermediate stage in the development
of structured language was likely to evolve, a stage with its own
evolutionary advantage. Before words can be grouped together in a
syntactic structure there has to be a process of segmentation: a stream
of words must be divided into appropriate discrete segments. Our work
shows that this stage was likely to develop anyway.

We consider a stream of spoken words and show that decoding can be done
more efficiently if the stream is segmented into appropriate chunks. Using
well known tools from Information Theory in a novel way we evaluate the
efficiency of decoding speech with and without various types of segmentation.
It is shown that it is easier to understand a stream of words if it is
divided up into the right sort of chunks.

A version of this talk is to be given at Harvard next month.


List of Colloquium Abstracts:
http://homepages.feis.herts.ac.uk/~nehaniv/colloq/