What is agnosia?
There are two stages to recognising something. The first stage uses the information you get from your senses about the way it looks, feels and sounds, to develop a picture of what it is. The second stage compares this to the information in your memory so that you can remember what it’s called and what it does. A stroke can affect both of these stages.
If your stroke affects how your brain processes the information you receive about an object, then this is apperceptive agnosia. If it affects the way you remember information about objects, this is associative agnosia.
Agnosia may only affect you in very specific ways. Some people, for example, find that although they can’t recognise an actual object, they can recognise a picture of it. Some people have agnosia for colour or faces. Having trouble recognising faces is known as prosopagnosia, sometimes called face-blindness.
Signs of agnosia
Apperceptive agnosia can affect any sense. So you may lose the ability to recognise objects by touch, sound or sight. It usually affects just one sense, so although you may not be able to recognise an object by looking at it, you may be able to by touching it.
Problems recognising an object by sight are most common. It’s not that you can’t see the object at all – if someone asks you to describe the object they’re holding, you’ll be able to tell them about some of its features. So you’ll know that it’s white, or that it’s got a handle, for example. But you won’t be able to recognise that it’s a cup. However, if you’re asked what a cup is, you’ll know exactly what it looks like and what it’s for.
If you have associative agnosia, you’ll have a full picture of the object you’re looking at, but you won’t be able to remember what it’s called. So you’ll often use the wrong name. Even if you’re told the correct name, you may not be able to explain what it’s used for.
What can I do about agnosia?
Usually if you have agnosia problems these will be picked up by your doctors or therapists whilst you’re in hospital or by your community team when you’re back at home.
If they haven’t been, and you start to notice that you may be having problems, then go back to your GP to get them properly diagnosed and assessed.
If these problems are making day-to-day life difficult for you, then you need to be referred to an occupational therapist. They will work with you to find ways to help you cope with them. They will also be able to suggest aids and equipment that can help you.
Find out more about getting help with cognitive problems after stroke.