Explore the brain

Your brain is the most complex structure in the known universe. It weighs just over a kilogram and controls absolutely everything you think, feel, say and do. Your brain is made up of lobes that control different functions. Scientists are learning about the brain to find new ways to beat the illnesses that cause dementia.

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Frontal lobe

What it does...

Your frontal lobe allows you to think, plan, solve problems, and make decisions. Your frontal lobe helps you to filter your emotions and control your behavior. It shapes your whole personality.

This part of your brain also helps you to focus your attention on different tasks and allows you to adapt to a changing situation.

How it’s affected...

If a person’s frontal lobe is damaged, their behaviour and personality may change. They may do or say socially inappropriate things, might not be able to consider other people’s feelings and could become unusually angry or short tempered, or seem to lack motivation. Frontotemporal dementia (or FTD) affects this area of the brain.

  • Personality
  • Emotions
  • Behaviour

Did you know?

In a construction accident in the 19th century, an iron bar passed through the skull of a man called Phineas Gage. He survived, but his frontal lobe was damaged and his behaviour changed a great deal. Doctors began to work out the function of the frontal lobe by observing these changes.

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Parietal lobe

What it does...

Reaching out and picking something up would be impossible without your parietal lobe. This is the part of the brain that allows you to see the world in three dimensions and tells you where your limbs are in relation to your body.

Your parietal lobe helps to combine all the information you collect from your senses so that you can make sense of what is going on in the world around you. It also helps to put things in order – like letters when we are reading and writing, and numbers in a calculation.

How it’s affected...

Damage to the parietal lobe can cause a person to misjudge distances, making it difficult to navigate obstacles and avoid bumping into things. It can also make it harder for someone to interact with objects in the world around them and lead to problems climbing stairs, putting on clothes, and even writing and drawing.

  • Ordering
  • Body Control

Did you know?

You have over 100,000 miles of blood vessels in your brain. They could wrap around the earth four times.

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Temporal lobe

What it does...

Your temporal lobe is involved in making sense of sounds and understanding the meaning of language. It also plays an important role in remembering and recognising faces, objects and scenes.

Inside the temporal lobe is an area called the hippocampus. This part of your brain allows you to make new memories and recall things that have happened to you, people you’ve met, and places you have been. It’s also involved in spatial memory and navigation, helping you to find your way around your world.

How it’s affected...

The hippocampus is often the first area of the brain affected by Alzheimer’s disease. As cells in this area become damaged and the hippocampus shrinks, it becomes more difficult to form new memories. A person with a damaged hippocampus may forget things they have only just said or done, while still being able to remember things from years in the past. They may have trouble finding their way around a place, particularly if it’s unfamiliar.

Frontotemporal dementia can sometimes affect the temporal lobe first. This can make it hard to remember the names of people and objects, recognise the meaning of words, find the right words or speak fluently. People who have this kind of dementia can have a lot of difficulty understanding language and speaking in a way that makes sense to others.

  • Memory
  • Language
  • Recognition

Did you know?

Research has found London black cab drivers have particularly big hippocampi – researchers think it could be because of all the routes they have to remember!

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Occipital lobe

What it does...

Your occipital lobe is the visual centre of your brain. This entire lobe is dedicated to allowing you to understand the things you see. It makes sense of all the signals sent from your eyes and allows you to interpret shape, size, colour and movement.

It then sends signals to other parts of your brain so that you can act on this visual information and recognise what you are seeing.

The occipital lobe also produces your dreams and allows you to imagine what something looks like without having seen it.

How it’s affected...

A rare type of Alzheimer’s disease known as posterior cortical atrophy (or PCA) can damage the occipital lobe. People with PCA can have problems making sense of what they see. They might have trouble reading, not be able to recognise familiar objects, and experience objects as having an unusual colour.

  • Vision

Did you know?

When you look at something, the image is flipped upside down onto the back of your eye. Your brain is able to process this image as if it was the right way round, put it in 3D and fill in the blanks without you realising!

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Nerve cells

Your brain contains many different kinds of cell that work together to form this amazing organ and make sure it runs smoothly. Nerve cells (or neurons) are in charge of sending messages through the brain. There are around 90 billion of these cells, which form hugely complex networks of connections with one another. All of your thoughts, feelings, memories and actions are the result of chemical and electrical signals being sent through these networks.

How do nerve cells become damaged?

All of the diseases that cause dementia damage nerve cells and interfere with the signals that produce a person’s memories, thoughts, feelings or movements.

This damage can happen in different ways. In vascular dementia, damage to the blood vessels in the brain means that nerve cells can’t get enough oxygen or food. In Alzheimer’s disease, dementia with Lewy bodies and frontotemporal dementia, the damage is caused by proteins that build up in or around nerve cells. This prevents the nerve cells from working properly, and eventually causes them to die. In Alzheimer’s disease these proteins are called amyloid and tau and they build up into harmful plaques and tangles.

Scientists are looking for ways to stop these proteins building up with the aim of slowing or stopping the damage.

Cell body Dendrites Axon Synapse
Tau tangles Amyloid plaques
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Important molecules that are the building blocks of our bodies. Many proteins do specific jobs like maintaining the structure of a cell, transporting important cargo around cells or helping cells to communicate.


Short branches of a nerve cell that receive signals sent from other cells and send them towards the cell body.

Cell body

The largest part of the nerve cell that contains many important structures as well as genetic information which tells the cell what to do.


The long tail of a nerve cell. Electrical signals travel along axons towards synapses.


The point at which one nerve cell connects to another. Chemical messengers are released to bridge the gap between nerve cells at synapses. There are trillions of these connections in your brain.

Amyloid plaques

Sticky clumps of amyloid protein that form around nerve cells in Alzheimer’s disease. These plaques are thought to trigger other changes, which cause damage to cells.

Tau tangles

Twisted strands of tau protein that stop nerve cells from working properly. These tangles build up in Alzheimer’s disease and some kinds of frontotemporal dementia.

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