Prosopagnosia: Inability To Recognize Loved Ones
Prosopagnosia or face blindness is quite a devastating condition. Imagine, suddenly finding yourself at a position where you are unable to recognize your family and friends. Your partner seems foreign and your child is not yours. You can imagine how detrimental that could be for all of the interpersonal relationships of the affected person. Apart from familiar faces, however, prosopagnosia can affect you in the worst imaginable way. You are not able to recognize yourself. Imagine, looking in the mirror, recognizing all of the features of your face, your hair, your smile, yet not able to put the pieces together to understand that it is, indeed, you. That can cause unimaginable confusion and distress.
What is Prosopagnosia?
Face blindness is not as well-known as other types of blindness and the majority of the regular public will probably not be able to recognize it just by its name. What is interesting about prosopagnosia is the fact that by impairing the face perception of the affected person, all of the other parts of visual processing are still working properly.
If you can imagine, prosopagnosia is quite a hot topic for neuroscientific research. It is especially interesting for those who work with the visual system and its processing. It is quite curious how we, as humans, tend to find out things about the proper functioning of the brain systems. We usually see something that doesn’t work properly and work from there. We start by recognizing what the disorder is, looking at its different variations and types. After we do that, we try to figure out the causes, the symptoms and where it’s located. We will look at the population in danger and the prognosis of it in the future. That’s how we are going to go around with prosopagnosia as well.
As mentioned before, prosopagnosia is face blindness. People lose their ability to recognize faces. Sometimes, apart from the inability to recognize faces, people also lose their ability to identify cars, places, or facial emotions. The discrimination to only not being able to recognize faces is actually less common than the combination with the other loses in the identification of objects or emotions.
If you can imagine, a number of social problems prosopagnosia is able to cause are quite big. Humans tend to recognize others by their face and their facial expressions.
Prosopagnosia is a neurological disorder. The part of the brain that responds to recognition of faces seems to be impaired in the condition. More on that later. People throughout the years thought that prosopagnosia can solely be caused by brain injury but nowadays we know that’s not necessarily true. Researchers have been able to find the genetic factor associated with a different type of prosopagnosia.
Prosopagnosia is another quite interesting topic for researchers due to the fact that it impairs quite a particular brain function – recognizing faces. In science, specialists argued about for such specificity for many years. Some scientists argue whether neurons – the basic building blocks of the nervous system – are able to be this specific in regards with their functioning.
Grandmother cells
Quiroga and his colleagues looked at the representation of a single neuron in the human brain. They said that we still do not know how we are able to recognize people or objects at such a fast pace and the functions of these neurons. Quiroga and his colleagues show how a certain type of medial temporal lobe neurons show activity after certain images of people are presented to people. They looked at the activity of eight different patients that had epilepsy and found that certain images elicited more activity than others.
Surprisingly enough, the image of the famous actress, Jennifer Aniston, was able to show neuronal activity every single time when her image appeared. Together with Brad Pitt, the neurons did not fire. When Jennifer Aniston was by herself, the unit started showing activity once more. The paper gained worldwide recognition due to the fact that it shows evidence for the ’grandmother cells’ – cells that are particularly specific to certain stimuli.
Prosopagnosia seems to be a neurological condition where that particular types of neurons play a big role. Or, in fact, their inability to play a role. We will look into the neuronal underpinnings for prosopagnosia in just a little bit.
Prosopagnosia: When?
First mentions of prosopagnosia came from around 1947 from Bodamer. He reported the presence of 2 people who were showing the symptoms of agnosia.
Agnosia is the inability to recognize things due to a brain injury.
He was the one who named the condition as prosopagnosia. ‘Prosopon’ stands for a face in Greek. It seemed fitting to him to call the disorder prosopagnosia since it involved recognizing faces.
Types of Prosopagnosia
Scientists used to believe that prosopagnosia happens as a result of brain injury. Now it’s not the case anymore. Specialists agree on 2 distinct types of the condition: Acquired and Developmental.
- Acquired Prosopagnosia: this type of prosopagnosia does, indeed, come from brain injury. Common types of brain injuries include encephalitis, stroke or head injury. This is the type that has been known for decades and the type Bodamer mentioned in his first report in 1947.
- Developmental Prosopagnosia: happens to be a neurodevelopmental condition. Seems to come from complications in learning. These difficulties cause the further inability to identify faces of close people. In comparison with the acquired prosopagnosia, developmental prosopagnosia is hereditary and is present in families which point to a clear genetic predisposition. The statistics show that around 2% of the human population is affected by some type of developmental prosopagnosia.
It is worthy of notice the recent connection that scientists made between prosopagnosia and Autistic Spectrum Disorder. It seems that certain problems with recognizing faces are present in those who have autism as well. Despite from that, developmental prosopagnosia seems to be a condition that stands on its own.
Causes of Prosopagnosia
As mentioned before, scientists identify two different types of prosopagnosia. They both have distinct causes. Acquired prosopagnosia results from brain injury. Certain brain areas acquire damaged and cannot function properly as a result. It is important to understand the anatomical location of the brain areas; their functions and the neuronal underpinnings and pathways in those areas. Developmental prosopagnosia has a genetic component and we need to know what is it exactly that causes it.
Acquired prosopagnosia: causes
The occipital lobe is the lobe of the brain responsible for visual processing. It is no surprise that some part of this lobe will be impaired in prosopagnosia. Occipito-temporal cortex seems to be the seat for the cause of the development of acquired prosopagnosia. Different studies have mentioned that this region is important for visual processing in those who do not have prosopagnosia. In fact, it seems to be specifically responsible for identity processing.
We can see how damage to this particular region can be crucial for the development of acquired prosopagnosia. Face blindness patients are able to understand that a face is a face – they can perceive it. What they seem to lack is the ability to put a name to that face, to identify it. That’s what the function of the occipitotemporal cortex seems to be.
Scientists have named a few particular areas within the occipitotemporal cortex that seem to be affected. One specific area is called the ‘fusiform face area’. It seems to show more activity for faces that are upright and less activity when the face is inverted. Apart from the fusiform face area, some other regions take part as well. In fact, a certain network of brain areas and regions plays a big role. These are areas include the superior temporal sulcus, occipital face area, prefrontal cortex and certain regions responsible for face processing in the anterior temporal lobe.
Haxby proposed a model that these various regions form a network with each of the regions being responsible for different parts of facial processing which includes facial emotion and facial identity.
Developmental Prosopagnosia: Causes
As mentioned before, developmental prosopagnosia seems to be run in families which shows a clear cut genetic predisposition. Many studies attempt to find the genetic cause for developmental face blindness. Scientists agree that heritability of face processing is quite clear. Despite that fact, we still don’t know the origin of the heritability.
Research shows that there is certain learning. This needs to happen in order for normal face processing to occur. Infants prefer to look at faces compared to other things. Once they do focus on the face, they keep eye contact for a long time compared to non-facial objects. Researchers proposed that when the child fails to develop these innate mechanisms properly – some sort of disturbances in the development of facial processing may occur. The neurological factors that take part in the acquired prosopagnosia are also important in here and might have certain abnormal functioning from the beginning. This could affect the development of developmental prosopagnosia.
How is Prosopagnosia Diagnosed?
In order to understand and diagnose face blindness, it is important to note certain symptoms.
Symptoms
- Confusion with characters in the movie and TV. Many of us seem to confuse characters on the big and small screen, however, you may notice that you do that a lot more often than other people.
- When greeting people, you cannot recognize them.
- When you fail to recognize a family member or a friend. Especially important if that happens when they greet you unexpectedly.
- Failing to recognize other people that surround you. Less prominent than if you fail to recognize a family member but could add some evidence for prosopagnosia. People from your social circles expect you to recognize them so when you fail to do so, it can be a sign of a problem.
- When you meet a new person, you focus on a certain feature rather than the face. Many people who suffer from prosopagnosia do that in order to avoid confusion and awkwardness in social situations.
- When somebody gets a makeover, you have difficult recognizing them. On the other hand, it may cause confusion if the person you remembered by their blonde wavy hair, went ahead and dyed it in red.
- You have experienced not recognizing yourself in the mirror and when looking at photos of yourself. This could be one of the tell-tales of prosopagnosia. The experience can be very disturbing but quite common with those who suffer from the condition.
If you experience any of these symptoms, please go ahead and see a professional who can help you with your confusion and concerns!
Prosopagnosia in Children
Children will experience similar symptoms as adults do, however, the result of having face blindness as a child may lead to certain consequences that can make a life of a child quite difficult. Adults are sometimes not able to handle it very well, you can imagine how taxing it can be on a child.
Fortunately, nowadays we know more about face blindness then we used to before. It’s easier to recognize and diagnose.
Children with prosopagnosia might not feel as much fear when meeting with strangers. Due to their inability to differentiate a stranger from somebody who is familiar with them, it could lead to hazardous situations. On the other hand, they will experience anxiety with the thought of losing their parents and teachers due to the fact that they recognize they might not be able to find them later. Kids suffering from the condition might not be able to make friends as easily and not enjoy social events. They might act differently in a home environment from everywhere else due to the comfort of being at home. Kids might not like participating in certain tasks at school, for example, they might feel anxiety with certain identifying games or ice-breakers.
What can you do as a parent?
First and foremost, be supportive and understand the difficulties that your child might experience in the course of their lifetime. Seek professional help in order to come up with strategies that will help them with identifying and recognizing people. You can help your child out by naming people when you walk into the room, for example. Place your child in a situation where he or she will feel comfortable and make sure that the adults responsible for the child when he or she isn’t with you, knows of the situation.
Treatment
As of right now, we don’t have clear treatments for those who suffer from prosopagnosia. All of the treatment goes into trying to figure out strategies that will help compensate the inability to recognize faces. Focusing on certain physical features and behaviors has been the goal of these types of therapies. Since people with prosopagnosia might develop other conditions like anxiety and depression, people often seek out mental health professionals for help and support. There is ongoing research that is trying to come up with the treatment for prosopagnosia. Awareness of other disorders that show certain symptoms of prosopagnosia can help with making life easier for those who suffer from it.
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References
Watson R, Huis in ’t Veld EMJ, de Gelder B. The Neural Basis of Individual Face and Object Perception. Front Hum Neurosci [Internet]. 2016;10(March):1–8. Available from: https://journal.frontiersin.org/article/10.3389/fnhum.2016.00066
Haxby J V., Hoffman EA, Gobbini MI. The distributed human neural system for face perception. Vol. 4, Trends in Cognitive Sciences. 2000. p. 223–33.
Dalrymple KA, Corrow S, Yonas A, Duchaine B. Developmental prosopagnosia in childhood. Cogn Neuropsychol [Internet]. 2012;29(5–6):393–418. Available from: https://www.ncbi.nlm.nih.gov/pubmed/23140142
Valerie is a psychology student who is trying to pursue a career in Cognitive Neuroscience. She is passionate about the brain and finds it fascinating. She loves learning about new discoveries and research that is going on in the world of psychology and neuroscience. One day she hopes to contribute to the scientific community!
