The Effects of Trauma on the Brain (Part Two) Posted March 21, 2013 by Heal for Life


Our brain has two halves, or hemispheres, which are linked by the corpus callosum, a large bundle of nerve fibres that allows the two halves to exchange information.


When people suffer trauma the link between the right and left brain (corpus callosum) is usually smaller. This means the two halves do not make decisions together so behaviour may be extremely emotionally based or alternately totally without feelings. Often a survivor of trauma will ‘flip-flop’ between the two. Healing creates greater integration between the two hemispheres so feelings are assessed by logical adult discernment. When we are healed our brain is rewired to create new neurons and pathways.

The right and left hemispheres in human beings can be quite independent. Many animals have the identical brain structure in order to help with their survival e.g. dolphins and birds. Birds will often sleep one hemisphere at a time so they are always awake to danger. Primates however have followed a different evolutionary path as both hemispheres are needed to perform different functions.

In the first eighteen months of life, development is concentrated in our right hemisphere which is concerned with emotional regulation and attachments.  Language follows as the left hemisphere becomes active. It is the left hemisphere that is largely responsible for language and the ability to speak, as discovered by Broca (this is known as Broca’s area). The left hemisphere is more linear and sequential, while the right can analyse multiple elements at the same time such as visual and imagination.

It is now recognised that these distinctions are not as clear or distinct as was once thought and the left brain can take over right brain activity to a certain extent and vice versa. Young children up to about the age of 10 years old can lose an entire hemisphere and the other hemisphere develops and takes over the lost hemisphere’s functions. This can allow the child to function normally.

For many years the left brain was thought to be the more dominant over the right, and therapies such as Cognitive Behaviour Therapy utilised the left thinking brain. However more recent research emphasises the ultimate dominance of the right brain. So although both sides of the brain are involved in emotion, the dominant role of the right hemisphere in defensive and negative emotions gives it “executive veto”, that is, power over the left hemisphere (Cozolino, 2002). People heal from trauma by accessing their right unconscious brain where the trauma is held.

Left hemisphere

Right hemisphere

Controls right body

Controls left body 





Analytic thought




Present and future

Past and present

Science and math

Art music



Sequential, explicit memory

Simultaneous, implicit memory

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