Sunday, 29 November 2015

“Neurons that fire together, wire together”

'How we learn

Neural networks and neuroplasticity

The human infant is born with approximately 100 billion brain cells, or neurons.
That number remains relatively stable throughout life, a fact that has contributed
to the long-held belief that the brain is fixed, or hard-wired, particularly post adolescence.
However, what is far from formed at birth and continues and changes
throughout life, are the tens of thousands of connections that form between each
one of these 100 billion neurons. The creation of these connections form neural
networks and their continual restructuring and change is known as neuroplasticity.
A neuron is a single cell, with a cell body, or soma, that houses the DNA and
proteins that guide its functioning. Each neuron has one axon that sends
messages and many thousands of dendrites that receive messages. Dendrites
appear like the branches of a tree, with more branches representative of more
connections. These connections represent learning.

On its own, a single neuron can achieve nothing - it takes many thousands
combined to generate every action, thought or memory we have. Neurons,
therefore, need to relate to other neurons. They achieve this by sending electrical
signals along their axon, which, upon reaching a threshold, release neuro chemicals
into the gap, or synapse, between two neurons. If the dendrites of
the receiving neuron have the appropriate chemical receptors, a connection will
be formed that results in the receiving neuron firing its own electrical charge,
which will be received by yet another neuron and, so, on goes the flow. One of
the founders of modern neuroscience, Donald Hebb, showed that neurons that
continued to activate one another in this way strengthened their connections, like
a path through a forest. “Neurons that fire together, wire together” became Hebb’s
Law and is a fundamental principle to how we learn 1.

In this way, our brains develop neural networks that embed and store our learning.
You have neural networks for every conceivable object, person, animal and
situation you have ever encountered. The neural network for your perception of
an orange will involve cells in different areas of your brain that code for the type,
shape, feel, size, smell and taste of an orange, along with whether or not you like
oranges, when and where you last had one, ways to use them, as well as abstract
variants, like the colour orange. It takes thousands of connected neurons in a
neural network for ‘orange’ to create this representation each time you see, think
about or just hear the word, ‘orange’. And that’s just an orange.

Your perceptions change over time. You acquire new information that adds to or
changes what you know about things and people in your world, or how you feel
about them. For example, a colleague may, surprisingly, disappoint you in their
response to an issue and this gives you a new insight into their motivation or
agenda. This new information requires your own neural network of this colleague
to change - literally, physiologically change - in order for you to process it. This
change shows the plasticity, or adaptability, of your neural connections and occurs
thousands of times each day as you experience your world - at both conscious

and subconscious levels.

Source: PageUp People

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