Tuesday, 30 August 2011

Language is based on what the brain can do – rather than the brain evolving to accommodate language.

As a result of a post What makes Humans Tick on Babel's Dawn my attention has been drawn to a paper Language Has Evolved to Depend on Multiple-Cue Integration by Morten H. Christiansen to appear in R. Botha & M. Everaert (Eds). The Evolutionary Emergence of Human Language, Oxford, Oxford University Press.
In discussing Language as a Culturally Evolved Linguistic System Morten writes:
A key question for language evolution research is to explain why language is the way it is, and how it got to be that way. The cultural evolution perspective suggests that the structure of language derives primarily from processes of cultural transmission involving repeated cycles of learning and use, constrained by the properties of the human brain. Thus, instead of asking, “Why is the brain so well-suited for learning language?”, we need to turn the question upsidedown and ask, “Why is language so well-suited to being learned by the brain?”
He goes on to say
Consequently, what has evolved is not a set of neural structures specific to language; rather, cultural evolution produces a system of linguistic constructions specific to a given speech community (i.e., a language).
This is really saying what I am trying to say on this blog – but coming from a very different direction.
The basic idea which underlies CODIL started as an attempt to design a sales accounting system in 1967 which would handle perhaps a quarter of a million very different customers, and perhaps 5,000 different products in a dynamic market. Details of the CODIL research and the sad reasons why the project eventually folded are given elsewhere on this blog.
To summaries the key factors: CODIL uses a conseptually very simple recursive set structure to represent information (there is no formal distinction between program and data) and a very simple “decision making unit” which scans through the stored information. Despite this simplicity it has been demonstrated to work, albeit sometimes on a small scale, on a wide range of non-numerical applications including some which would classify as artificial intelligence, or involve fuzzy logic or dynamic learning.
Its relevance to the evolution of language (I will be posting further information about this in September) is that it appears that both the information structure and the processing routines will translate comparatively easily from the sequential central process of the original model onto a neural net where the amount of information done by any one node is acceptably small. It could well be that the processing power already demonstrated in the original sequential model can be reproduced in a neural net and is sufficient to support many aspect of human natural language.
If a CODIL type model can be sustained for the inner workings of the brain and can be extended to support the plethora of human languages, this would fully demonstrate the feasibility of the ideas represented in the above quotations.
However don't expect me to come up with all the answers. I am an old age pension who retired from university research over 20 years ago, with deteriorating eyesight, and with no access to academic library or computer facilities. As far as I am concerned this blog site will have been successful if I can persuade someone younger and fitter than I am, and who has adequate resources, to follow up the ideas.

Babel's Dawn and the Evolution of Vocalisation

A copy of Edmund Bolles' book, Babel's Dawn, A Natural History of the Origins of Speech, has just arrived and tells a fascinating story of how humanity has developed from just being a great ape over the last six million years. He uses a series of verbal snapshots to reconstruct what life was like for the Last Common Ancestor and their descendants. At each stage he discusses the findings of recent research, the uncertainties of reconstructing the past of our species, and the many gaps that still have to be filled. For each episode there are brief notes that re-direct you to the extensive bibliography.
So far, so good, but I have two major problems with the book. Before I retired I used to review books for the New Scientist, and also was the book review editor for an online discussion forum called HICOM, which was an early UK based interactive forum discussing a very wide range of subjects relating to the way humans interacted with information and computers. This book might even have been included on the possible review list as it is about how humans came to communicate with each other.
The first question I would ask in picking up any book to review myself, or to allocate a suitable specialist to review, is “What is the market for this book?” In the case of Babel's Dawn I am not sure. The story is told as if the reader was was walking through a museum with dioramas representing different periods in the past, with a verbal commentary being given as you go. For school children and the generally interested public the book would have been far more effective if each vista had been described with an associated picture with the pre-human figure in a reconstructed view of the landscape, and the amount of more formal scientific discussion significantly reduced. On the other hand, the serious scientific reader might find the faction approach annoying and the lack of an index frustrating. However my knowledge of the modern US university student book market is very limited, and it could be a useful reader, rather than reference book, in introducing a subject which many students might find controversial because of their religious beliefs – a problem which is far less an issue in the UK.
I also had a serious problem with Edmund's treatment of vocalisation and its relevance to speech, Without vocalisation there can be no speech as we know it and in my opinion the book fails to examine the evolutionary pressures that lead to the changes in the vocal tract which makes speech possible.
To be fair there is a very real difficulty in reconstructing this aspect of mankind's part as sound is about as ephemeral as one can get, and there is no possibility of any direct fossil evidence. Even indicator evidence, such as the changes in a tiny bone in the larynx, is hard to find, as the bone is rarely found in fossil deposits. In practice all one can do is to speculate on the evolutionary pressures that might lead to the evolution of vocalisation, which in turn lead to speech.
So lets step away from the book and speculate as to how the story might have been told.
Undoubtedly a very important aspect of the evolution of the human body was the move from living in forests to living in far more open and dryer environments. As the forests dried out they would have initially fragmented, depending on soil, altitude and drainage conditions locally, leading to a series of forested “islands” that would eventually vanish entirely. Forest species trapped on these islands, including our ancestors, would either have to adapt or become extinct. Such environmental changes, temporally trapping creatures in small habitat areas which are in the process of disappearing, are powerful evolutionary workshops and if we look at the human body most of the changes make sense. Descending from the trees and walking in more open areas is an obvious driver for changes in our lower limbs. Such changes also free our forelimbs for gathering food, tool making and throwing things. As a vulnerable animal, which no longer has trees to climb to escape, and who is not agile enough to catch fast moving prey or run from the larger predators, early man would need a degree of cunning and planning which will be helped by a larger and more imaginative brain.
The relevant evolutionary pressures are not so obvious when it comes to vocalisation. The modern human has a very powerful and flexible vocal system – which can produce a wide range of noises, including whistles and clicks, with significant control over pitch, volume and timing. However a modern human language may only use about 30 phonemes to express meaning – so it would seem that our vocal system has developed to a far greater extent than is necessary to support speech.
Of course social bonding might have been a factor, as Edmund suggests, but our great ape ancestors would almost be using facial expressions, body language, grooming and gestures to communicate when they are close together, and it has been suggested that the reason that we have developed whites to our eyes is to make it easier to “read minds” by observing our social companion's eye movements. It is easy to see why, if vocalisation changed for other reason it might have been adapted for social communication but it is not obvious why, if stronger social bonding was an advantage, that this should not have been done by a cultural change affecting the existing bonding techniques, rather than the far slower method of, for example, evolving a more versatile larynx.
One must realise that when man's forebears first came down from the trees the use of sound would have had its snags. Using sound is a very public way of communicating – and while someone might be able to signal to a colleague on the other side of a valley one must remember that every prey or predator in the neighbourhood would pick up the sound and turn to look at where the sound indicating danger or food came from.
However there is one area where improved vocal ability could have a significant advantage and that is if used as a tool when hunting. After all, in evolutionary terms getting enough to eat must be the top priority after avoiding being eaten yourself. If the aim is to catch a medium-sized herbivore such as an antelope a good technique is to drive the animal towards an ambush, but this needs a number of hunters working as a team, and this involves signalling at a distance. The ambushers need to tell the drivers when they are ready while it could increase success if the drivers warn the ambushers that the prey is approaching the killing area. Initially an ape-like grunt to indicate that the ambusher is ready might be adequate – but over time evolutionary pressures on the prey would alert it to the fact that ape noises can indicate danger – so the signalling method would need to change. As the long time battle between prey and hunter continues the hunter must improve his tactics – so an innocent imitation call of an owl hooting, or the whistling call of a bird would be a far better signal. But as the hunters vocal skills develop it will become possible to lure other animals by making, for example, mating calls at the right time of year.
If we consider that the ability to mimic other animals is an advantage to the increasingly intelligent hunter we now have an evolutionary pathway that will lead to the development of a very wide range of vocalisations - which is what the human species possesses. But this also leads to a possible start for using vocal symbols to communicate. After all, using an animal call to symbolise an animal is the equivalent of using a simple picture as a symbol in the early days of writing. Perhaps, in the same way that pictorial languages simplifies to alphabetic languages using words, vocal languages developed in a similar way by using special combinations of sounds to symbolise names of individual members of the group, perhaps naming them after animals. Vocalisations might then be extended to other objects. Further moves towards the rudiments of language would involve reducing the number of phonemes needed to be accurately recognised and generated by combining groups of sounds into words.
But that is a story for another day.

Sunday, 28 August 2011

The Old Codger comes up for Air

The recent lack of posts on this blog is because August has been rather chaotic for me. On Doctor's order I have to loose weight and get plenty of exercise and frequent rural walks - plus doing shopping by walking rather using the car - takes time. A visit to the hospital brought some good and bad news. My left eye, which was hit by glaucoma a few years ago, is stable and if I needed to use it I can still read the computer screen with 4 times magnification. The problem is that my "good" right eye has started to develop a cataract, and while it has not developed far enough yet to justify an operation I am finding reading smaller text difficult.  While my wife is getting much more mobile after a knee operation, I find that I still spend as much time shopping and preparing the meals, and the number of days spent on social activities has increased   because she can get around better!

One particular problem this month is that both my wife and I are hoarders - and last year we had new insulation installed in the loft. This involved downloading much of the stuff stored up there into the spare bedroom - where it has stayed - as one of the effects of old age is that neither of us want to climb up a ladder to put it back. This would not matter except that we are having an Australian visitor to stay over September - and it was only last night that the room was clear - after many visits to the local charity shop, and filling bins for recycling.

On the computer side I find that I have far more that I would like to do that I have time to do it. For example my genealogy site has over 3,500 pages of information about Hertfordshire and Hertfordshire people, and I am slowly working through the towns and village pages upgrading them, and introducing new material. The problem is that even if I averaged one town or village a week I would be approaching 90 years old before I finished - and in reality the process is more like the never-ending task of painting the Forth Bridge. At the beginning of August I decided to cut back on this activity but have been "rewarded" by an increased flow of challenging questions. To give myself a break I have shut down the "Ask Chris" facility throughout September.

Despite all the above I have been thinking quite a lot about this site - with quite a lot of background reading and even starting to draft an occasional blog - but nothing has emerged on blog. So I have decided to move this blog back up the priority list.

By the end of the August I plan to post a review of Edmund Bolles new book "Babel's Dawn: A Natural History of the Origins of Speech" and early in September I plan to post an article suggesting why my earlier work on CODIL actually provides a possible insight into the brain's "symbolic assembly language".  I may also post details of the old school reunion at Dartington Hall - which was a very unconventional school which greatly stimulated my interest in science - which encouraging the idea that the established viewpoint was not always the right one.

Thursday, 4 August 2011

The explosive evolution of langauge

Greg Laden's blog has just posed the following talk by Mark Pagel under the title "How language transformed humanity"

I am very interested in the way that language suddenly appeared on the scene, and the accelerating speed at which it has helped to transform the world in which we live. While Mark clearly recognizes the importance of cultural factors I was not happy with some of his supposed facts - and while I think that the concept of "social learning" can be useful in discussing the cultural explosion that coincides with, and is possibly driven by, the appearance of language I was not always happy with some of his examples. As a result I published the following comment on Greg Laden's blog.

Oh Dear - he really runs down the capability of our ape and early human relatives and misses the significance of fact that many of the areas where there are many languages with few speakers involve primitive societies.

I would agree that once language reaches a certain tipping point it greatly facilitates the transfer of information between generations - and also motivates further cultural development of the language itself. Basically you get what in chemistry I would call an auto-catalytic reaction. Once the tipping point is reached the each development in language skills makes further development easier - and there is an accelerating chain reaction. This will not only affect language - but also all the cultural activities and objects of the time.

The question which he does not address is what came before "language" which he does not really define, except by a crude analogy. Once the human line split off there has been a steady increase in brain size and almost certainly vocal abilities - and the majority of these changes will have been before "language" evolved.

What were the evolutionary pressures to drive these "improvements" if "language" did not exist. Humans were hunting on the African plains and needed skill and good team working to catch and kill larger animals. For instance in setting an ambush those lying in wait need to alert the drivers that they are ready. What better than sound - but if the sound is obviously human the prey will evolve to treat obviously human utterances as a danger - so what could be better than to evolve the ability to mimic other animals such as an owl hooting, etc., and to make a wide range of clicks, whistles and yodels, and to be able to change pitch

Before a proper language had developed there could well have been a simple hunting symbolic language which would involve a very wide range of phonemes - and each hunting group might use them in different way because they were hunting different prey in different environments. Recent research on attempting to date the development of language in Africa start with the assumption that the more primitive languages use a larger number of phonemes. Such an origin might also explain that the majority of languages with very small numbers of speakers involve tribes which are either still hunter gathers or were so until comparatively recent times.

Where did the tipping point come. My own guess is around the camp fire of an evening, when the hunters returned - and started to use their hunting calls to tell the story of the day. Children would learn about the methods and dangers of hunting without being exposed to them - thus acquiring a wider range of hunting skills. Once language reaches the stage of "Tell about the time you killed the lion, Daddy" the art of story telling has got underway. Legends are born and those of the Australian Aborigines go back several tens of thousands of years to the Dream Time, when some now extinct animals were alive.

An interesting feature of this model of language development is that language starts from a cultural tipping point and there may be no simple genetic factor at all. OK - more brain capacity could help handling far more concepts - and better vocal skills might make it easier - but the fact that the more advanced languages use less phonemes would suggest that a wide range of vocal skills is not essential for language.

Monday, 1 August 2011

The Curse of Knowledge

In this week's New Scientist (30 July) Richard Fisher writes:

There are many virtues in being ignorant. We all aspire to have the smarts, but it now seems knowing less can sometimes be an asset. It can make you a better teacher, a more perceptive student and a happier person overall.

The article includes details of a study by Nate Kornell, of Williams College, Williamstown, Massachusetts:

Kornell and Son staged a trivia quiz for mathematicians and historians. The pair asked these academics 90 questions about other experts in their field. Try two of the questions yourself: is Johannes de Groot a famous mathematician? What about Benoit Thoron? Would you answer yes, no, or don't know?

When asked about mathematicians, those in the same field were more likely to give a definite answer, yes or no. Yet while they might know their differential equations inside out, the mathematicians' confidence in naming members of their field was unfounded. They gave more wrong answers to these questions than the historians, who were more willing to confess their ignorance. But the historians weren't humble when it came to their own field - they made the same blunders over the questions about their peers. “They assumed their knowledge was great, but it wasn't in this case” says Kornell. “Experts should say 'don't know' in their own field of expertise more often.”

Are you honest about the limits of your knowledge? How did you answer the mathematician question? De Groot is a Dutch mathematician who died in 1972. Thoron is fictional.

My experience in developing CODIL is very relevant. My first job was as an information scientist working on research and development issues in a large international organisation. I was dealing with scientists and managers (up to board level) with very different backgrounds and specialities. The idea of one information worker having complete knowledge of what the organisation was doing was ridiculous. Everyone in such a large company, including the information workers, is ignorant of much of the detail of what was going on. What the information worker needs is the ability to identify sources of information when required – plus the “teaching skills” of being able to interpreting specialist reports in more widely understandable words.

I then moved to the data processing department of a very large commercial company and took my approach to knowledge and ignorance with me. I was aware that there were specialists in selling aviation fuel to the United States Air Force, in selling central heating oil to domestic houses, in selling tarmac to road builders, etc. I was also aware the the market place was dynamically changing. To me the idea that a group of systems analysts and programmers could produce an exact model which not only accurately reflected today's requirements but also allow flexibility to meet the commercial challenges that might appear tomorrow was something in cloud cuckoo land. Based on my experience of manual information process I took the idea of ignorance in my stride and suggested the answer was not to draw up an exact model of the invoicing process but rather to model the way that sales staff thought about invoicing. The aim was to allow each sales specialist within the company to directly control his area of the market without the need to conform to a globally pre-agreed approach which would always be incomplete and out-of-date.

How this idea later expanded the design of CODIL is describe in detail elsewhere on this blog. However the difficulty I had in getting the idea accepted is directly linked to the concept of ignorance. The computer establishment was, and still is, based on the idea that it is necessary to precisely predefine the application in advance. Ignorance of the application is automatically taken as a sign of incompetence. There is no doubt that much of the opposition to CODIL was that it was taken for granted that it is impossible to program a computer from a position of ignorance of the task – therefore I must have created the computer equivalent of the perpetual motion machine.

This blog is trying to take the CODL ideas further and say that in as far as you can model the human brain you can use the model to handle situations involving ignorance in a way that mimics the way that humans also tackle the problem .
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There is an example where too much knowledge has slowed down the progress in the “Brain Storms” on this blog. Over the last week or two I have been trying to complete the first stage of remapping CODIL onto a neural net. Most of the basic processes move relatively easily but one basic facility – that of asking a question of the knowledge base – would not go in a way that I felt was satisfactory if one wanted to move to parallel processing.. Basically CODIL uses the question as “criteria” (a little bit like a conventional program) and the knowledge base “file” (long term memory) was loaded statement by statement into the “facts” (equivalent to human short term memory). The problem was that in originally designing this part of CODIL I had too much knowledge about how conventional computers work and had incorporated this in the design.

Once I had realised the “block” existed I went right back to first principles. In fact it is obvious that the important thing, in terms of brain activity, is the question – so this should go into the Facts (short term memory). Once there the knowledge base file is asked to say what it contains which is relevant – rather as if it was acting as a kind of program, rather than as data. A new “Brain Storm” should appear in the next few days covering this point.