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Personality
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Memory
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Ordering
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Emotions
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Vision
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Language
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Body
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Spatial
Awareness -
Behaviour
The Human Brain
Brain Tour
Click the hotspots to discover how your brain works and the effect dementia has on it.
Join us on a tour of the brain, the most complex structure in the known universe. From movement to memory, find out what different parts of the brain do, and how they can be affected by dementia.
Alzheimer's Research UK scientists learn more about the brain and dementia every day and the Brain Tour showcases our progress. With hundreds of
projects
underway looking at causes, diagnosis and treatment, you are helping us bring about breakthroughs to change lives.
What it does
Enclosed by the tough protective casing of the skull, our brains are the centre of our nervous systems. The brain monitors and regulates our actions and reactions. It constantly receives information from our senses, rapidly analysing and co-ordinating our responses to things we see, hear, touch and taste.
The brain is also our centre of learning. It forms and stores our memories. It's involved in speech, abstract thought and consciousness as well as informing our personality and emotions. An adult brain weighs about 1.5kg (3.3lb) and contains about 90 billion nerve cells. As well as nerve cells our brains have about 90 billion other cells, plus blood vessels to help supply the nutrients and oxygen it needs. During
dementia
, nerve cells in different areas of the brain become damaged and eventually die. A lot of research we're supporting aims to stop this damage and protect the brain from harm.
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Personality
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Memory
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Ordering
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Emotions
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Vision
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Language
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Body
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Spatial
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Behaviour
What it does
The largest part of our brain, the cerebrum plays a role in memory, attention, thought, language and consciousness. It's also involved with our senses and movement.
It's made up of tightly folded grey matter, giving the brain its wrinkly look, and white matter, which is made of bundles of fibres that transport information - like bundles of electrical wires.
How it's affected
Dementia with
Lewy bodies (DLB)
affects the cerebrum. In DLB small, round lumps of proteins build up in the grey matter. These spheres harm nerve cells, causing the symptoms of DLB including hallucinations and fluctuations in consciousness.
This area can also be affected by vascular dementia, the second most common cause of dementia after Alzheimer's.
Vascular dementia
is caused by blood flow to the brain being reduced. Blood carries essential oxygen and nourishment to the brain and without it brain cells die.
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Personality
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Emotions
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Behaviour
What it does
The frontal lobe is involved with our personality, behaviour and emotions.
It's involved in choosing between good and bad actions as well as predicting the consequences of our actions. It suppresses unacceptable social behaviour. It helps us decide on similarities and differences between things. It is also involved in storing long-term memories.
How it's affected
Frontotemporal dementia (or FTD) affects this area of the brain.
There are different types of
frontotemporal dementia
. Some affect the frontal lobes early on and patients behave inappropriately and often experience personality changes. It's thought that frontotemporal dementia is caused by proteins building up in the brain, harming nerve cells.
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Ordering
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Body
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Spatial
Awareness
What it does
The parietal lobe helps us put things in order - like letters when we are reading and writing, and numbers in a calculation.
It is responsible for our 'body sense' e.g. knowing where our arms and legs are in relation to the rest of our bodies. It also helps us see, recognise and locate objects in three dimensions e.g. so we can pick things up.
How it's affected
This part of the brain is affected by posterior cortical atrophy (PCA) a rare type of Alzheimer's.
Because this part of the brain helps us see, when it becomes damaged in PCA patients experience difficulties seeing what and where things are. Like in the more common form of
Alzheimer's disease
, it's affected by proteins building up and damaging nerve cells.
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Memory
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Vision
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Language
What it does
The temporal lobe helps us understand things we see and hear around us. It's involved with remembering and recognising faces, objects and scenes. It is also involved in language, including naming things and remembering words.
The temporal lobe has a role in memory too - including memories of things that have happened to us. Inside the temporal lobe is an area called the hippocampus. The hippocampus makes new memories and helps us find our way, remembering places and layouts.
How it's affected
The hippocampus is affected by Alzheimer's disease.
Two proteins, amyloid and tau, build up and damage nerve cells. This build up starts in the hippocampus before spreading to other brain areas. The damaged nerve cells in the hippocampus mean this part of the brain can’t function properly, which can lead to the early symptoms of
Alzheimer’s
– memory loss and disorientation. The temporal lobe is affected by
frontotemporal dementia
, a rare type of dementia. There are different types of frontotemporal dementia. Some affect the temporal lobes early on and those affected have problems with language, speech and factual knowledge about the world.
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Vision
What it does
The occipital lobe interprets information from our eyes.
It determines the shape, colour and movement of the things we are looking at. It also produces the dreams we experience when we sleep.
How it's affected
This area of the brain is affected by a rare form of Alzheimer's called posterior cortical atrophy (PCA).
Because this part of the brain helps us see, when it becomes damaged in PCA, people can experience difficulties seeing where and what things are. Like in the more common form of
Alzheimer's disease
, it's affected by proteins building up and damaging nerve cells.
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Language
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Body
Control
What it does
The cerebellum helps control our movements, including balance and posture. It's also involved in attention and language.
How it's affected
Like other areas of the brain, the cerebellum is eventually affected by Alzheimer's and other dementias.
Most dementias are 'progressive', which means they get worse over time. People's symptoms get worse as nerve cells become damaged in more and more areas of the brain. The two hallmark
Alzheimer's
proteins build up in this area and damage nerve cells.
