Cognitive effects of brain injury
The cognitive effects of a brain injury affect the way a person thinks, learns and remembers. Different mental abilities are located in different parts of the brain, so a brain injury can damage some, but not necessarily all, skills such as speed of thought, memory, understanding, concentration, solving problems and using language.
You can find out more about the behavioural effects of a brain injury below. Our Psychological effects of brain injury and Managing anger after brain injury booklets provides more detail, and the Headway helpline will be happy to talk through any specific questions you may have.
Problems with memory, particularly short-term and ‘working memory’, are common after brain injury. Some people may be unable to remember faces or names, or what they have read or what has been said to them. New learning may be affected, while previously learned skills may still be intact (e.g. multiplication tables learned at school). The damaged brain is now unable to organise and remember new material.
It is important to note that memory problems cannot be overcome simply by practising, or by going over lists of information repeatedly. Playing memory games and engaging in memory exercises will not do any harm, but do not expect these to bring about an improvement. New practical or ‘hands on’ skills can be learned by repeating them frequently, but this learning will not transfer from one skill to another.
Go to our memory problems page for more information.
Language loss (aphasia)
This may be ‘receptive’ (difficulty making sense of what is said or read) or ‘expressive’ (difficulty finding the right words to say or write), or both.
This can be very frustrating for the person and for others, and patience is needed on both sides. Remember - just because a person cannot express themselves, does not mean they do not need or want to be heard.
Impairments in visual-perceptual skills
The person may have difficulty making sense out of ordinary pictures and shapes, finding the way around a building, or drawing or constructing objects. Some people have difficulties recognising certain objects (agnosia), such as human faces (prosopagnosia or 'face blindness') (see the Headway factsheet Prosopagnosia: face blindness after brain injury).
Although vision and hand control may be good, the person may appear to be ‘seeing’ only part of the scene. Sometimes people can only attend to one half, usually the right side, of objects, even though they can still see the other side if prompted. This condition is known as visual neglect and can cause people to only eat the food on one side of the plate, only shave one side of the face or even dress only one side of the body.
Impairments in visual perception may mean that a person cannot assess the speed of oncoming traffic accurately. It is important therefore to make sure that they are safe when crossing roads.
Reduced initiative and problems with motivation
Problems with getting started on tasks are common, and can often be mistaken for laziness. These problems may also be a symptom of depression.
Reduced concentration span
This is very common, and can also be affected by memory problems. Completing tasks can be a problem, and the task may be abandoned before reaching the end. The person may initially appear eager to start a task but then lose interest very quickly.
Reduced information processing ability
It may be difficult for the person to organise facts in their mind, particularly if there are also memory problems. ‘Information overload’ can be quickly reached, and can cause frustration and anger.
Repetition or ‘perseveration’
The person may be unable to move on to another topic in the same conversation, or they may return to the same topic over and over again. They may also repeat the same action, appearing unable to break the cycle.
Impaired reasoning may affect a person’s ability to think logically, to understand rules, or follow discussions. The person may easily become argumentative due to lack of understanding.
Impaired insight and empathy
Impaired insight and empathy can cause difficulties in accurately perceiving and interpreting one’s own and other people’s behaviour and feelings. Putting oneself ‘in someone else’s shoes’ can be almost impossible.
Insight, also referred to as self-awareness, is the ability of a person to observe and reflect on their own thoughts and actions. Brain injuries, especially injuries to the frontal lobes, often cause this ability to be significantly affected. This can be a particular problem for both brain injury survivors and their family, friends and carers. It can be distressing for survivors, because they may struggle to understand why people are restricting them from doing certain things.
Families, friends and carers can find it problematic and upsetting because the brain injury survivor may behave inappropriately without being aware that there is anything wrong with their actions.