The term visual agnosia

1. Visual agnosia is a condition in which a person can see an object clearly but is unable to recognise and name what they can see.
2. It is caused by damage to the parts of the brain that make sense of what the eyes send in, not by damage to the eyes themselves.

The symptoms of visual agnosia

1. Objects cannot be named by sight
   1. A person can look straight at a familiar object, such as a set of keys, and be unable to say what it is.
2. Sight itself is unaffected
   1. They can often describe the object in terms of its shape, colour and texture, and can copy it accurately, yet still cannot say what it is.
3. Other senses still allow recognition
   1. Handling the same object, or hearing the sound it makes, will often let them name it straight away.

The term prosopagnosia

1. Prosopagnosia, sometimes called face blindness, is a condition in which a person can still see a face clearly but cannot recognise whose it is.
2. It is often linked to damage in the temporal lobe, and it is an inability to recognise faces while other aspects of visual processing and intellectual functioning remain intact.

The symptoms of prosopagnosia

1. Familiar faces are not recognised
   1. A person may fail to recognise close family, friends or colleagues when they meet them face to face.
2. The face is still seen clearly
   1. They can see and describe the eyes, nose and mouth without difficulty, but cannot say whose face it is.
3. Their own face can be affected
   1. Some people do not recognise their own reflection in a mirror or their own face in a photograph.
4. Everything else stays intact
   1. Object recognition, reading and reasoning are unaffected, so the difficulty is with faces alone and not with sight or intelligence.

Telling the two conditions apart

1. Visual agnosia affects the recognition of objects, while prosopagnosia affects the recognition of faces.

The impact of damage to the pre-frontal cortex

1. The pre-frontal cortex is the region at the very front of the frontal lobe.
2. Damage here leaves movement, speech, memory and general intelligence largely intact, which is what makes its effects so easy to underestimate.
3. Emotional processing is affected
   1. A person's emotional reactions may become flat, or may not fit the situation they are in.
4. Decision-making is affected
   1. Personal choices about money, work and daily life can become poor or impulsive, even though the person can still reason and calculate normally.
5. Social behaviour is affected
   1. A person may say or do things that others find inappropriate, and may struggle to plan ahead or stick to a plan.

The evidence from Damasio et al. (1994)

1. Damasio et al. (1994) reconstructed the path the tamping iron took through Phineas Gage's skull in 1848 and worked out which regions it had destroyed.
2. The damage fell in the ventromedial region of both frontal lobes.
3. Twelve living patients with damage in the same region showed the same profile, with calculation and abstract reasoning intact but emotional processing and personal and social decision-making impaired.

Turning this into marks

1. Name the condition and quote the detail that identifies it, such as Aisha recognising her manager's voice but not her face.
2. Say what is still intact as well as what is lost, because normal sight and normal object recognition are what separate the two conditions.
3. The mark most often lost is the application one, so never answer in general terms when the question names a person.