Understanding brain hemisphere dominance and neurological conditions

September 17, 2024

In this article

Couples tend to divide household tasks according to who does them best (or who hates them least!). Perhaps you cook and your partner (or housemate) loads the dishwasher. Maybe you clean the bathroom and they do the ironing. Maybe you shop and they take out the bins.

Occasionally, if they’re away or unwell, you might find yourself responsible for your partner’s tasks. You’re quite capable of doing them – but maybe not quite as well since the jobs feel unfamiliar.

Your brain is similar. It’s divided into two hemispheres – left and right – which play distinct yet interconnected roles in controlling various bodily functions and cognitive processes.

What does a ‘dominant hemisphere’ mean?

One hemisphere of your brain is more active or efficient at controlling certain activities. It’s the dominant hemisphere for that task.

Some brain functions are the sole responsibility of one hemisphere. The right side of your brain, for example, controls movement on the left side of your body and vice versa.

Language, for example, is mainly controlled by the left hemisphere – known as left hemisphere language dominance. Emotions, on the other hand, tend to have more involvement from the right side of your brain.

That said, most functions (like memory) require the coordination of several areas in both hemispheres of your brain. It isn’t an ‘either-or’ situation – it’s ‘both-and’.

Neurological conditions and hemisphere dominance

The dominance of one hemisphere can influence the presentation and progression of various neurological conditions.

Stroke

A stroke occurs when a blocked or burst artery prevents blood flow to your brain. Deprived of oxygen and nutrients, your brain cells die.

Stoke can significantly affect a person’s life, depending on which area of the brain is affected.

A left-hemisphere stroke can cause:

Paralysis or weakness on the right side
Loss of sensation on the right side
Difficulties with speech and understanding language
Loss of the right field of vision in both eyes
Difficulties with organisation, reasoning, calculation or analytical skills
Changes in mood and behaviour such as becoming more cautious or hesitant
Depression
Difficulty reading, writing or taking in new information.
Memory problems.

A right-hemisphere stroke can cause:

Paralysis or weakness on the left side
Loss of sensation on the left side
Difficulties with depth perception
Loss of the left field of vision in both eyes
Difficulties reading maps or finding things
Changes in behaviour such as impulsivity, inappropriate actions or lack of concern for others
Depression.

In stroke rehabilitation, therapies are often tailored to the specific issues caused by the stroke. Someone with a left hemisphere stroke may benefit from speech therapy to improve their communication skills while someone with a right hemisphere stroke may need occupational therapy to improve their spatial awareness.

Epilepsy

Epilepsy is a medical condition that disrupts electrical activity in the brain, scrambling communication messages and resulting in seizures, which can change someone’s movement, behaviour and awareness.

There are many different types of seizures. Partial seizures – now known as focal onset seizures – start in a specific part of the brain in one hemisphere only.

Each hemisphere of your brain has six different parts, known as lobes, which are responsible for particular brain functions. The temporal lobe, for example, organises things like hearing, language and speech production. An epileptic seizure in this part of the brain may affect someone’s ability to talk or understand others during the seizure.

The left hemisphere tends to be more prone to seizures, according to recent research.

Traumatic brain injury (TBI)

A traumatic brain injury (TBI) refers to brain dysfunction caused by an outside force such as a blow to the head. It may happen due to a sporting collision, a car accident or an assault.

A TBI can damage one or both hemispheres, leading to different kinds of impairment. Damage to the right side of the brain may cause movement problems or weakness on the left side. Damage to the left hemisphere may affect communication abilities.

Rehabilitation will usually focus on improving functions associated with the damaged hemisphere.

Harnessing hemisphere dominance at Neurofit Brain Centre

Hemisphere dominance is critical to the brain’s functional organisation and significantly influences neurological conditions. But it’s not only about one side or the other – it’s also about how well they work together.

The good news, though, is that your brain is constantly learning and adapting. This is a fascinating branch of science known as neuroplasticity. It means we can stimulate the weaker areas of your brain to encourage improvements in function.

To see how this could help you, please book an assessment today.

Disclaimer

All information is general and is not intended to be a substitute for professional medical advice. Neurofit Brain Centre can consult with you to confirm if a particular treatment approach is right for you.