A honeybee’s brain weighs one mg and contains fewer than a million nerve cells
Insects with minuscule brains may be as intelligent as much bigger animals and may even have consciousness, it was claimed today. Having a brain the size of a pinhead does not necessarily make you less bright, say researchers.
Computer simulations show that consciousness could be generated in neural circuits tiny enough to fit into an insect’s brain, according to the scientists at Queen Mary, University of London and Cambridge University.
The models suggest that counting ability could be achieved with just a few hundred nerve cells, it is claimed.
And a few thousand would be sufficient to make an animal a conscious being, rather than an automated ‘living robot’.
‘Animals with bigger brains are not necessarily more intelligent,’ said Professor Lars Chittka, from Queen Mary’s Research Centre for Psychology, writing in the journal Current Biology.
‘We know that body size is the single best way to predict an animal’s brain size.
‘However, contrary to popular belief, we can’t say that brain size predicts their capacity for intelligent behaviour.
‘In bigger brains we often don’t find more complexity, just an endless repetition of the same neural circuits over and over.
‘This might add detail to remembered images or sounds, but not add any degree of complexity. To use a computer analogy, bigger brains might in many cases be bigger hard drives, not necessarily better processors.’
Differences in brain size between animals can be extreme. A whale’s brain can weigh up to nine kilograms and be packed with more than 200 billion nerve cells.
Human brains vary in weight between 1.25 kilograms and 1.45 kilograms, and have an estimated 85 billion neurons.
In contrast, a honeybee’s brain weighs one milligram and contains fewer than a million nerve cells.
Many size differences existed only in specific brain regions, the scientists pointed out.
This was often the case in animals with highly developed senses, such as sight or hearing, or which have an ability to make very precise movements.
Increased size allowed the brain to function in more detail, finer resolution, and higher sensitivity or to achieve greater precision.
Research suggested that bigger animals may need larger brains simply because there was more to control. More nerves were needed to move bigger muscles, for example.
Much ‘advanced’ thinking could be done with very limited numbers of neurons, the scientists claimed.
Via Daily Mail