We agree wholeheartedly with the sentiment expressed by Grethe Hooper Hansen ("Play is Vital as Brains Develop", Letters, August 8) that less emphasis should be placed on formal learning and testing in the early years. However, we feel compelled to comment on her claims on brain development and hemispheric dominance, which have no basis in fact.
It is true that there are cortical and subcortical regions in the human brain, and a left and a right hemisphere, but their function and development up to adulthood is still not fully understood. There are many different cortical regions and, in the human brain, these undergo a period of development that is more protracted than that of subcortical regions. Some parts of the cortex, including the frontal cortex, which is responsible for cognitive functions such as planning, decision making and self awareness, continue to develop during the teenage years and into the twenties. The limbic (emotional) system develops earlier, but it is not accurate to say that it stops developing at the age of seven. For example, the amygdala, which plays a crucial role in experiencing and perceiving emotion, changes during adolescence.
As regards the concept of left brain-right brain, the truth is far more complicated than the simple story about the left brain being analytic and the right brain creative. While it is true that one hemisphere dominates the other, both sides of the brain work together in most situations.
It has been argued that education favours left-brain modes of thinking, which are logical and analytic, while downplaying right-brain modes of thinking, which are creative and emotional. While encouraging a wide variety of modes of thinking is probably a good thing, it is purely metaphorical to call these right-brain or left-brain modes. People with no right hemisphere are not devoid of creativity; those with no left hemisphere, although often unable to produce language, can still be analytical.
The neuroscience of teaching and learning is developing at a rapid pace and has many implications for education. But progress can only be made when good sentiments, such as the need for more emphasis on play in the early years, are based on sound science. The neuroscience clearly shows that there is no advantage to be gained by an early start to formal education.
Sarah-Jayne Blakemore and Uta Frith, Joint heads of the developmental group at the Institute of Cognitive Neuroscience, University College London, and authors of `The Learning Brain: Lessons for Education'.