To start us off we’re going to look at a case you may have heard of before from Oliver Sack’s popular book ‘The Man Who Mistook his Wife for a Hat’.
Dr. P was a musician turned teacher, a charming man with a quirky sense of humour, and it was as a teacher that he started noticing some problems. They were small at first, such as not being able to recognise students by their faces but using their voices instead. Later on they began to develop into something a little stranger… He would see normal everyday objects, such as parking meters, as peoples faces, and address them like people. However, he didn’t get this problem checked out until he developed diabetes and, knowing it causes eyesight issues went to see an optometrist. Instead, he was referred to a neurologist, Oliver Sacks.
In this initial examination Dr. P was presented with scenic images and asked to describe them but he was only able to pick out small details at a time, or vague shapes and colours. When shown an image of sand dunes he describes things that weren’t even there, like a river, and a group of parasols. Afterwards, when getting up to leave, he went to pick up his hat and instead grabbed his wife’s head – hence the catchy name of the book. Obviously, a very curious case. In some ways he showed signs of severe neurological issues, yet he was a brilliant musician and functioned well in his work as a teacher.
In a later visit, Dr. P was presented with faces of people he knew, friends and family, and could recognise hardly any of them. Interestingly, if they had a very unique feature, such as a large moustache, it would become easier for him. But even more than this, he couldn’t recognise everyday objects like a glove or a rose. He saw them perfectly, could describe their shape and colour, but not say what they were.
So what caused this? Well, Dr. P was suffering from a condition called ‘visual agnosia’. This occurs when there is damage to the parts of your brain that are responsible for seeing and recognising objects. In your brain you have your primary visual cortex, which is where the information from your eyes first goes to, then it splits off into two paths. These are known as the ‘what’ and the ‘where’ pathways because that’s what they determine, what and where things in your vision are. In visual agnosia it’s the ‘what pathway’ that is damaged, which is usually in the anterior cortex (the top and back of your brain).
Other specific areas being damaged can lead to more specific symptoms as well. For example, not being able to recognise faces, a disorder known specifically as prosopagnosia, can be from damage to an area called the ‘fusiform face area’, which is involved in facial recognition. Nowadays, this is quite a well-documented disorder and there have been lots of studies into its causes and specific cases too. There’s even an episode of House which features it!
Have you all every heard of this case before? If you’re interested in stuff like this I definitely recommend getting Oliver Sacks book because it features lots of short cases featured in a very entertaining and understandable way.