9.3 Flashcards
What is visual agnosia?
loss or impairment of the ability to recognise visual stimuli due to brain injury
What are the types of visual agnosia we studied?
Apperceptive, associative, Prosopagnosia, Simultanagnosia, Topographical agnosia, Colour agnosia, Agnosic alexia.
What is apperceptive agnosia?
People with this disorder cannot perceive the individual parts of a stimulus as a meaningful, unified whole. For example, they cannot identify a dog that was shown to them, but could identify a dog by touch. They must rely on non visual senses to identify objects.
What is associative agnosia?
People with this disorder can describe an object or even draw it or copy a picture of it, thereby indicating that they can correctly perceive the physical characteristics of an object. However, they do not know what they have drawn or even explain what it does or is used for.
What is prosopagnosia?
An inability to recognise a familiar face, including their own when seen in a mirror or photograph. The person can, however, use other visible characteristics to recognise people, such as gender, age, the way they walk (gait), a tattoo, a characteristic hairdo or even face information such as a moustache or expression. The ability to recognise other types of visual stimuli tends to be relatively unaffected.
What is Simultanagnosia?
An inability to recognise more than one object at a time in a scene that contains more than object. For example, if a banana and an orange are presented together, only one of the two is perceived.
What is Topographical agnosia?
An inability to find one’s way around familiar environments. The person typically has a good memory of the layout and specifics of the places well known to them, such as their own neighbourhood, but they are unable to navigate their way around without getting lost.
What is colour agnosia?
People with this disorder will typically be unable to name the colour of an object when seen, provide a list of objects of a specific colour, or to sort objects into colours.
What is Agnosic alexia?
An inability to recognise or comprehend written or printed words. Also called word blindness and pure alexia, people with this disorder have severe reading difficulties while other language skills associated with writing, talking and listening tend to remain unaffectedv
How can agnosia’s be treated?
Agnosia is specifically associated with damage along neural pathways that connect areas that process perceptual information. There is no direct cure for visual agnosia however rehabilitation is an option. For example, someone with apperceptive or associative visual agnosia may be learn how to identify different types of objects by touch
