Make your own free website on Tripod.com
Brainpower

Brain Structure

Home
Brain Structure
Mature Minds
Brain Shapers
Memory Shapers
Brain Prescriptions
Positive Psychology
Mind-Body Connections
Some Key Researchers
Learning
Metacognition
Motivation
Online tests and games
Staying Sharp
In the News
Contact

Brain Cells

neurons.jpg

Neurons are spidery structures that have a cell body and thousands of appendages that can either receive (dendrites)2 or send (axons)3 electro-chemical impulses to and from other nerve cells across the synaptic gaps4. The interconnectivity between brain cells is the power that allows us to make new associations and continually add to them all our lives. Our thoughts and actions are the traffic of these signals between cells. While healthy brains lose some cells as they age, the loss is not dramatic and is limited to very specific areas (Goldman, 1996). So inevitable loss of brain capacity with age is greatly overstated. In fact, rather than losing brain cells as we get older we can usually extend our neural connections as long as we stay healthy and intellectually active.

See also Mature Minds page.

 

Click here to read more about brain plasticity -

The Brain from Top to Bottom - McGill University.  '

'Learning depends on the plasticity of the circuits in the brain - the ability of the neurons to make lasting changes in the efficiency of their synaptic transmission.'

 

Other Brains

Insects, birds, reptiles and mammals have the same basic brain cells as humans, with the only difference being their number and organisation.  However wildlife has a range of different and amazing capabilities. A bee can communicate, dance, learn, defend its community, adapt to gravitational forces and detect the difference between millions of scents. Computer analysis of a skylark's song reveals that it composes as many as twenty different Mozart-like symphonies in a day. Mammals have complex social systems, have emotions, have reasoning powers and a range of intricate communication systems. We often forget that an anthropocentric view5 of the natural world is a very limiting one.



5  Anthropocentrism means viewing everything in terms of human values and humankind as the ultimate creation.


2 Dendrites (Greek word for tree) form a spiky fringe around the cell body allowing each cell to receive signals from more than 100,000 others.

 

3 Axons are the nerve fibre projections from the brain cell that transmit impulses to the dendrites of other neurons. They can even extend for as much as 3 feet - the equivalent to a kite with a 40ft tail!

 

4 Synapses are the tiny gaps at the terminals of the axons across which electro-chemical signals travel - a system we share with all other animals from the jellyfish up.

 

Visit Spring Into Life's  BrainPower page for video clips.

wonderfulbrain.jpg

The Cerebral Cortex

 

The key to the brain's amazing power lies in the most evolutionary advanced part of our brain - the cerebral cortex - the 2mm wrinkled outer coating which, spread out flat, would cover approximately four A4 sheets of paper. The bulkiness of the brain comes from the myelin sheathes on the axons that speeds up  communication between cells.

The hardwiring of ‘wisdom’ is dependent on the axons – the long string-like extensions of the cells or ‘cables’ that allow neurons to link up to other cells in different parts of the brain. Myelin production peaks around 50 but continues more slowly till the end of life. It is this ongoing ‘superhighway’ construction that creates better co-ordination between different brain regions, better integrated use of the left and right hemispheres and supports neurogenesis and wisdom in the second half of life.

 

See the Brain Shapers page.

 

'We carry our evolution inside us, within the different structures of the brain, structures built in different eras.... each one designed to maintain stability in its organism as animals moved from the sea to land, to the trees, to the savannahs of Eastern Africa, to Fifth Avenue.'  Ornstein and Sobel