Cognition, the brain and dementia

We all have behaviours.

According to the dictionary, behaviour is “the way in which we act, or conduct ourselves, especially toward others”.

Dementia complicates everything. It affects the brain which impacts the ways in which a person is able to communicate their needs. Dementia affects behaviour.

This website was created for people with dementia, their families and caregivers. It aims to:

  • Provide an overview of behavioural and psychological symptoms of dementia (BPSD).
  • Help you understand the approaches healthcare professionals use to assess and treat these symptoms.
  • Offer techniques to help caregivers respond to behaviours in ways that will enhance the quality of life for the person with dementia.

Step one is defining and describing three key terms:

1. Cognition (click here)

Cognition refers to ‘thinking processes’ within the brain. The term ‘cognition’ (cognitive) covers many functions within the brain such as:

  • Memory
  • Thoughts
  • Planning
  • Organization
  • Attention and concentration
  • Visual and spatial ability

One distressing cognitive symptom associated with Alzheimer’s disease is memory loss and may include:

  • The inability to remember parts of one’s own life.
  • Forgetting things that have happened recently.
  • Failure to recognize family members.

There are exceptions, but with most dementias you will notice a change in cognition followed by behavioural or psychological changes.

2. The brain (click here)

The brain is in charge of our:

  • Feelings
  • Thinking
  • Memory
  • Behavior – or actions

People who have dementia will experience changes in their brain and may develop psychiatric symptoms including changes in their personality and their behaviour.

3. Dementia (click here)


Dementia is not a specific disorder, it is a general term that refers to cognitive issues such as memory and thinking ability. There are many causes of dementia including:

One thing all dementias have in common is that they cause impairment in a person’s cognition. They are progressive illnesses that affect the brain and worsen over time.

In the early stages of dementia people will have difficulty with everyday functioning like:

  • Keeping appointments.
  • Having conversations.
  • Misplacing things.
  • Managing finances.

Eventually, symptoms will progress to a point where the person may forget very basic functions such as how to get dressed.