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Understanding Left brain Right brain function can help you understand how the damage after brain injury might affect a person’s ability to carry out tasks; and what support might be needed, particularly to encourage development of new pathways.

This video “The Divided Brain” is a wonderful, though challenging, introduction to understanding the separate and combined left brain right brain function.

Today follows on from last week’s introduction to left brain right brain function with more about the specific functions of each hemisphere.

The Workings of Left Brain Right Brain Functions

The following table lists a range of left brain right brain functions.

A simple start to what each hemisphere does: The left brain generally works on detail and specifics, the right brain takes a more global approach, both work together for optimal efficiency. Left brain logical, Right brain creative.

Again a ‘brain disclaimer’ needs to be remembered. Most of the time the functions are on the side of the brain listed – but not always. Sometimes genetic makeup, damage, neuroplasticity, will mean the functions are on the opposite side to that which is expected.

The Example of Recognising Faces

Generally while the left brain examines and puts together specific facial features to try and recognise someone, the right brain will look at the overall face and features, then link it as a whole to the person.

The right side is generally more efficient in accurately recognising faces and therefore it can be difficult to recognise even very familiar faces after damage to the right side of the brain.

The article “How We Recognise Faces” gives a brief outline of a study done to identify the parts of the brain that assist us recognise faces. This helps explain the role of both hemispheres in recognition.

Sometimes after brain injury (common in dementia) a person is not able to recognise faces at all this is called Prosopagnosia.

Table of Left Brain Right Brain Functions

As you read the following list consider how damage to either hemisphere might affect a person. Any of the functions within each hemisphere may no longer be possible.

It is often the left brain functions valued in today’s world, seen as the business and economics hemisphere. The arts and creativity tends to be less valued, and seen as more a right brain function. As we saw last week both left brain and right brain work together for the best outcomes.

By understanding a bit about left brain right brain function you can then work out what might be difficult for a person who has damage on either side. This article while more about learning has further information about left brain right brain function in an easy to follow table

Unusual Outcomes of Left Brain Right Brain Function:

Alien Hand Syndrome

Left brain right brain function is responsible for some of the more sensational and talked about outcomes of changes to the brain. One particular outcome you might read about is called “Alien Hand Syndrome”. This is rare yet captures imagination, and clearly demonstrates different left brain right brain function.

It appears to literally be a case of the left hand not knowing what the right is doing, and one hand behaving independently of a person’s will. People report one hand taking the opposite action to the other, for instance one hand chooses clothing the wear, the other selects different. One hand behaving carrying out a task while the other is being destructive, hitting self or others.

Left Brain Stroke

A study in Germany of people admitted to hospital for stroke showed that people who had a left brain stroke were more likely to be admitted to hospital than those with a right brain stroke.

Why?

Well you can read more in this article but in summary it is thought that possibly left side strokes are more obvious particularly because the speech and language centres are on the left side.

People who have a stroke or major damage on their left side appear to see everything, even mild circumstances, as a catastrophe. A person with similar damage to the right side can appear to not take things seriously enough or being overly optimistic.

The Story of the Judge with Left Brain Damage

There is a case outlined in “Mapping the Mind”  by Rita Carter that provides an example of a person after left side brain damage.

It was reported that a Judge in America had significant damage to his right hemisphere following a stroke. He returned to work and although he was unaware of his difficulties, his colleagues raised concerns. The Judge was not able to consider and give appropriate weight to all the evidence, he would give erratic sentences. It was reported that people who had committed serious crimes were at times allowed to go free. Others who had committed more minor crimes might be given long sentences. He was eventually sacked. At this time his brain damage served as some advantage as he remained content, during what could have been a difficult time.

Key Points about Left Brain Right Brain Function

An easy to remember summary;

• The Left hemisphere is the Reading (w)Riting and (a)Rithmetic side.
• The Right hemisphere is the Sensory, Spatial, Synthesing side.

As can be seen from the table above each side has different functions, and a different way of operating.

• Each side can work alone.
• Neither is more important
• Function is more efficient when both hemispheres work together
• Damage to either hemisphere can have significant changes to the way tasks are carried out.

It would be great to have more examples of the outcome of left and right brain injury. Please share any examples you wish to in the Comments below. Also any comment you might have on left brain right brain function.