Essays
Mirror Neurons club
Mirror Neurons link*****
Marilyn's article
Tim Koder
A important part of the theories further supported by the mirror
neurons is that the adaptability and learning potential of the cortex
gave teaching a chance. The reason why man's understanding of the
physical world and his own mind has accelerated is that teaching and
knowledge facilitates extra learning. For example, internet technology
has allowed people to learn more than was easily accessible before,
giving rise to individuals' original thoughts in response. The potential
for these thoughts existed before the prompting information was
available.
Now imagine the spread of information slowed down, as it was when
contact between humans was less frequent. How easy is it to create
new words for a common language if your language so far is only 100
different noises? Explanation of a new concept is still tricky now we
have hundreds of thousands of words.
There was no area of entirely dormant brain in my forehead waiting
to be tickled by reading the articles relating to the mirror neurons. (I
hope) It was doing something else first: my response to what I read
depends on my previous learning. The apparent waste of brain power
in earlier humans may be explained by the fact that if nobody tells
you what to do, you have to work things out for yourself, something
which most people would agree is more difficult!
A crude model, based on the idea of the hippocampal 'grandmother'
cell, would see learning as a reorganisation of neurons which respond
to single stimuli into a small network which can then recognise a more
complicated concept, and interact with other small networks to create
new concepts.
Such 'single concept' neurons do exist; but how do these single
neurons fire? Visual information regarding, for example one's
grandma, must already have been processed through many synapses
and involved many of these smaller networks before a
grandma-specific response can be elicited in the single cell.
Recognising a grandma or raspberry-blowing tongue in your face are
both very difficult objects to recognise, really.
Semir Zeki's 'A Vision of the Brain', which first attracted me to
neuroscience, is important not only for visual processing, but also for
a general understanding of brain function, and offers some
mechanisms by which such mirror neurons may be stimulated and
interact to produce 'thoughts'. The importance of the 'mirror neuron'
is that it had so far been impossible to break down the mechanisms of
thought in those areas of brain involved in the highest levels of
cognition and hypothesise using mechanisms of learning and memory
which have been better validated for areas of the brain which are
evolutionarily older.
The mirror neuron for a specific stimulus is not in exactly the same
position in each monkey: if the brain were so limited, learning would
only be a matter of evolution. The evolution of a larger brain gave
humans the potential for greater learning capacity than monkeys,
particularly by continuing the evolutionary enlargement of the cortex,
the most plastic brain tissue. I would argue that this potential was not
being wasted 100,000 years ago, merely that the lack of taught
knowledge meant this processing capacity had to be put to more
immediate uses than mathematics or the refining of printing
technology.
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