Thursday, 28 February 2013

Chimpanzees Enjoy Brain Puzzles

Recent research carried out at Whipsnade Zoo, only a few miles from where I live, and has been reported by the BBC. The game involved poking red dice along tubes until they fell into a container. The BBC report says:

Researcher Fay Clark, from the society, said they noticed the chimps were "keen to complete the puzzle" for its own sake, regardless of whether or not they received a food reward.
"This strongly suggests they get similar feelings of satisfaction to humans who often complete brain-games for a feel-good reward," she said.
"For chimps in the wild, this task is a little bit like foraging for insects or honey inside a tree stump or a termite mound, except more challenging because the dice do not stick to the tool."
Researchers created higher "levels" of challenge by connecting many pipes together, and making them opaque so the dice or nuts could only be glimpsed through small holes.
This is yet another example that we think in the same was as out fellow apes - the main difference being that we have bigger brains (which can store very much more information) and we can also far more effectively pass information from one individual to another using language.

The full article, Effect of a Cognitive Challenge Device Containing Food and Non-Food Rewards on Chimpanzee Well-Being, is published in the American Journal of Primatology, and contain useful information and prior references to related work.

Wednesday, 27 February 2013

How evolution made us the way we are

The talk about the mechanics of evolution I gave yesterday went very well, and I looked at the factors that shaped our body (walking on two legs, the hands, the voice box, and loosing hair) when we moved from the African forests to the savannah. I then discussed why a brain is very expensive - and why animals would not evolve a large brain unless there was a very real advantage. I then discussed how a rudimentary language, a tool-making culture, and a bigger brain could lead to the kind of explosion in apparent human intelligence (as judged by surviving artifacts) that started sometime between 50,000 and 100,000 years ago.

If you need to prepare a similar talk, aimed at a lay audience, you may find the slides of the talk (pdf file) helpful. Most should be reasonably self explanatory apart from a few slides at the end which very briefly look at a model of how the brain uses memories to make decisions - which relates to some of my own research. A more detailed paper will appear on this blog shortly. 

Wednesday, 20 February 2013

How the Human Brain works – concept cells, memodes and CODIL


I am really Excited.

I can't wait to tell you about it. 

I am currently preparing a talk How Evolution has made us the way we are – and I had a problem. You can't really assess how evolution has affected the development of the human mind unless you have a clear model of how the brain processes and stores information. I have already, in earlier brain storms on this blog pointed to the black hole in brain research where very significant amounts of work is being done round the edge of the problem but where there is no good model of how electrical pulses in the brain are translated into human language or behaviour. I have also discussed at length how work on a highly unconventional language called CODIL (COntext Dependent Information Language) may throw some light on the issue and recently introduced the term memode (memory node - see The Evolution of Intelligence - From Neural Net to Natural Langauge) to try and demonstrate a possible mechanism. However there was still a major gap in the model if it was to serve as an adequate model for understanding how the evolutionary pressures worked.

So What has Happened???

The trigger to filling the gap came from the article “Brain Cells for Grandmother” in this month's Scientific American, by Rodrigo Quian Quiroga, Itzhak Fried and Christof Koch. (see also Concept Cells: the building blocks of declarative memory functions by Rodrigo Quain Quiroga). This research involved monitoring the activity of single neurons in the medial temporal lobe of epileptic patients undergoing assessment prior to surgery. It was observed that a single cell might respond to different pictures of a single individual, while remaining inactive when pictures of other people were shown. In one case a neuron was found which responded to three different pictures of Luke Skywalker, his name (either in writing or spoken) and interestingly to a picture of Yoda, another character in the film Star Wars.

One of the problems I was facing in earlier brain storms was the relationship between the information in the working memory (called the Facts in CODIL) and the main memory which contained the items of information and the links between them. On reading "Brain Cells for Grandmother" the relationship became clear. Information is stored in the links, and the main memory and the working memory are one and the same – the difference is that the working memory is defined by the links which are currently active. I can now tie my model into the neural network in the brain and the change of viewpoint provides throws light on the following aspects of the working and evolution of the human mind..
  • The “virtual” information represented when the top neuron in a memode is active is simply the sum of all the subsidiary memodes (recursively) which are linked to the memode. Thus each concept is at the top of a tree of subsidiary concepts. There is no one location where information about a concept is stored.
  • The senses trigger bottom up activity in the memodes, the objects  we “see,” “hear,” or “smell” being the highest level memodes activated.
  • The CODIL Decision Making algorithm maps onto a process in which active memodes can trigger top-down activity in related but initially non-active memodes. (Basically the brain can decide that if “A” and “B” are active “C” should be active.)
  • Consciousness (the information we are actively aware of – and equivalent to the Facts in CODIL) is the sum of the information represented at the time by the top active memodes.
  • Learning involves the linking of the top active memodes to generate a new higher level memode. (In fact it looks as if deciding what not to learn and what to forget becomes the critical factor than learning in building memories.)
  • If we assume that some decisions are made sequentially - with a series of memodes triggered in a predefined order – the model could support at least a simple spoken (i.e. sequential) language. The experience with CODIL being able to handle significant non-trivial information processing tasks is relevant here. This points to an evolutionary tipping point leading to the explosive growth of both language and other special skills.
For more details read on ....