Identical twins have always been fascinating. How can one tell them apart? How do two individuals with identical genetic information in their body cells grow up to be separate different people? Previous work with twins showed that the influence of their genetics and environment on average each contributed 50% to their behaviour.
Modern work on the cells of the brain indicates that there is much more flexibility than previously thought and that in many ways the brain is very malleable. Not only do nerve cell processes change with time, but new nerve cells can appear. So although there is an intrinsic pattern laid down initially, this is continually being modified as the result of experience of environmental stimuli. As no two people’s experience is identical, even twins, their brains gradually diverge, becoming more and more different. Recent work by Julia Freund and others on mice has examined this process in greater detail than ever before.
This neuroplasticity is important because it provides the potential for change under the right circumstances: For example in education, recovery after injury and in therapy. For example learning a foreign language or to juggle three balls in the air can be shown to lead to changes in the pattern of brain scans. During meditation in some cases specific changes can be seen- in other words the brain can change itself! This has been called self-directed neuroplasticity.