Cognitive Domains

Cognitive domains is a term to describe categories of the brain's function. The brain is usually categorised into the following functional areas:

• Memory
• Executive functioning
• Attention
• Language and communications
• Sensory and motor functions.

Together, these cognitive domains give us the capability to go about daily life. When someone has a stroke, it is likely that at least one, and often more, of these cognitive domains will be impacted.

A neuropsychologist can assist with assessing damage to these cognitive domains and advise on various types of cognitive therapy that may assist.

Memory

Simply, memory is your ability to remember "stuff". This "stuff" generally falls into three categories:

• Who, what and why - which is known as semantic memory
  
  This allows you to remember who people are and why you care about them. It also allows you to remember poetry, song lyrics and paintings.
  
• When and where - which is known as episodic memory
  
  This allows you to remember specific events you have experienced.
  
• How - which is known as procedural memory
  
  This allows you to remember how to do things. All of our skills, whether simple or complex, that we learn are recorded in procedural memory.

Memory is one of the important cognitive domains as it gives us the ability to learn and re-learn skills. Through memory, we are also able to recall facts and experiences, and to recognise people and things.

If memory is affected through a stroke (or other brain injury), a person can become apathetic about learning and/or withdrawn or confused due to all the apparently new information and experiences coming at them.

Executive Functioning

Executive functioning is named because it represents the sort of skills that an "executive" needs to master to be effective. Our brain can be considered the "executive" that drives our body's functioning. It needs to be able to manage our time, make judgements about what is happening, make decisions about what to do and plan how to do things.

In Richard Leviton's book, Brain Builders, he talks about the anatomy of what he calls Brain Power as having the following aspects: Mental strength - the strength to concentrate on and solve difficult or challenging mental tasks (e.g. maths calculations, weighing the alternatives for a tough decision) Mental flexibility - the ability to shift from one kind of mental task to another (e.g. determining which shares to purchase and then having a conversation about your holiday) Mental endurance - the ability to sustain the mental focus on a task, this involves maintaining your inspiration, keeping track of the logical progression of the activity and keeping the effort through until completion (e.g. planning and organising a party involves a month or more of activities to make it come off brilliantly). You need to be able to manage distractions, fatigue and boredome to ensure that the task is completed. Mental coordination - the ability to project manage all the tasks that you need to do, keeping the appropriate level of focus on each, so that all get completed in a timely fashion.

These aspects are another way of thinking about what the cognitive domains of executive functioning and attention (below) involve.

Attention

Attention is your ability to focus on the task at hand, work out what needs to be done and see it through to completion. Attention can be considered the governor of your brain, placing your focus in a particular direction. Many stroke patients suffer from a degradation in this ability.

Two factors that affect attention are your arousal (how engaged you are) and the speed with which you can mentally process information. If you aren't engaged, or can't work out what you are doing or how to do things, it's easy to be distracted onto something else.

Research by L Stankov (published in Psychology and Aging in 1988) has indicated that there are different aspects to attention. These are:

• Concentration - the ability to purposefully direct your attention for a sustained period of time (e.g. reading a book for several hours)
  
• Vigilance - the ability to keep a look out over an extended period of time for rare events (e.g. watching for a pot to boil over)
  
• Divided attention - the ability to perform two or more tasks simultaneously (e.g. talking to someone whilst you're knitting)
  
• Selective attention - the ability to focus on one thing and block out another (e.g. reading a book whilst other people int he room are talking
  
• Search - the ability to find a particular thing within the context of similar things (e.g. finding a word in a word search puzzle)
  
• Alternating attention - the ability to switch between activities (e.g. reading a book and monitoring the time so you can leave for an appointment on time).

The loss of this ability can significantly inhibit a stroke patient's ability to return to work, as they can be easily distracted and unable to complete their assigned duties.

Language and Communications

Next of the cognitive domains is language and communications. There are two aspects to this. The first is the physical ability to communicate and the second is the mental capability associated with communications. Different parts of the brain control each of these aspects.

Physically, we communicate in several ways. Most obvious is our ability to speak and the inflexions that we place on our words. But there are also the physical gestures that reinforce the intent of the speech, or that are standalone communications in themselves.

Sensory and Motor Functions

Our senses are the means by which we experience the world outside of our bodies. They are our source of input and the means by which we process that input information. Our sensory systems include sight, hearing, smell and touch.

Our brain also controls the motor function of our body - or how we get our body to do what we want it to do. What can be difficult for stroke patients is the understanding that whilst they see impacts in their bodies, these are actually a result of the brain injury, and not damage to the affected part of the body. However, this is good news too, as because of brain plasticity, there is hope for some degree of recovery.