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Lessons

8b - Impaired Facial Recognition

Posted by Helen St Clair Tracy in Level 8 - CVIs Ventral
Published: 28/01/2020, 12:05am | Updated: 24/02/2020, 7:37am

Video Link: https://vimeo.com/392274567

Image of right side of the brain with the right temporal lobe coloured green.Image of right side of the brain with the right temporal lobe coloured green.

In most people's right temporal lobe is a mind-store containing all of the faces they know. In some it is on the other side.

As with everything in your brain, things that are most well-known, through repeated meaningful experiences (Level 2), have the strongest memories. With facial recognition, these are the faces of the people you have had the most repeated meaningful experiences of seeing. They might be family members and close friends, or they might be people you have never met...

Nelson Mandela's face is widely recognisable, even to people who never met him in person.

Knowing the faces of people you have never met is relatively new. Only two hundred years ago most of us would only know the faces of people we had seen in person, here's why...

The Brain & Faces - A Brief History

  • Before 1826 when the first photograph was taken, the only way to see faces of people you had not actually met was through artists' drawings and portraits.
  • From 1891 onwards, as cinema developed, more and more and people could see moving images of people whom they'd never met.
  • Then, from 1927 onwards, television started entering people's homes
  • Thereafter, of course, we have computers, then smart phones and tablets

Let us think about that - and our brains. Less than two hundred years ago the faces a brain processed and remembered belonged only to people it had physically come across.

What happens when you see or meet someone? They are in a certain place and a given context. This context might be linked to another known person, or a certain activity. All these bits of information form networks in your mind connecting together everything you know about that person.

Think back only two hundred years, before photographs and when transport was very limited. How many people would the average person know? How many faces would be in the brain's right temporal lobe face store?

Now think about today, the characters on multiple television shows and in cinema, on YouTube and other internet platforms, plus all the people you know, not just those you have actually met, but met through social media.

That's a lot more faces for our minds to store.

So, where facial recognition is a challenge, one thing that could be tried is to go back in time, sort of back-to-brain-basics. Repeated, meaningful experiences with real people.

What about the process of Facial Recognition?

Imagine this woman is someone you knowImagine this woman is someone you know

Let's imagine the woman in the above picture is someone you know.

The picture is processed in the occipital lobes and sent to your temporal lobes, to your memory bank of faces, to find a match. Once a match is found, that gets presented to your frontal lobes, to alert you to think whether you know her, and if so from where and in what context. The faces of the people you pass that are not recognised are automatically filtered out, unless there is something particularly striking about them. In these cases your frontal attention will divert or be diverted to make you look at them, but not because they have been recognised, but because something about their face raised a little flag in your mind.

Assuming the woman is recognised, in brain terms that means a match has been found between the image you are looking at, and a specific one in your mind-store of faces. Next your brain will immediately start further searches to let you know where you know her from. All this is done so fast you don't know it's happening, apart from the times you meet, see or pass someone you recognise, but can't quite place. That figuring out where you know them from is literally your brain searching all over for other matches, to help you identify them.

Image of right side of the brain with the occipital lobe (red) temporal lobe (green) and frontal lobe (blue) marked.Image of right side of the brain with the occipital lobe (red) temporal lobe (green) and frontal lobe (blue) marked.

That journey from the occipital lobe via the temporal lobe (on the ventral stream) and on to the frontal lobe follows one of the main anatomical pathways of the brain, a sort of super-highway, called the inferior longitudinal fasciculus (pronounced fa-sick-you-lus). It is called a white-matter pathway because the information travels through the white matter - or cabling - of the cerebrum (lesson 1a).

Why Is Recognising Faces Important?

It is important to be able to identify individual people, and recognising their faces is one way we do this.

  • 1. Safety - the relationship between the brain and the human face is fundamental (we will explain a little more about this in the following lesson 8c on difficulties recognising facial expressions). At at a very basic level, known people need to be seen as safe or unsafe. Known liked people, who are recognised, may be approached. Someone unknown, or known to be cruel or unkind, when recognised, may be avoided.
  • 2. Supporting the Group. We do things in groups, whether it is family groups, friendship groups, work groups, sports groups. Very few people can survive completely alone. To perform well as a group, we need a way of getting to know each other, and this requires being able to recognise each other.

In summary, our need to recognise people, and our means of achieving this through facial recognition is about survival of the species. In modern society it seems much more sophisticated, but think about how much more our brain has to process. It is still doing what it does best, protect us.

Separately, and a better question for modern society is:

Why are difficulties recognising faces a problem?

The answer is that it creates social difficulties, because:

  • People who are known may be ignored, causing irritation
  • People who are not known, may be mistaken for people known, causing embarrassment

Think of these difficulties in a child with CVI, who has never known what it is like to recognise faces, but is not aware they can't do it, because they have no reasons to think people see differently to them. Friends become offended, and adults irritated. The child may be vulnerable if unable to find a known safe adult.

Not being able to recognise people by their faces does not mean they are not known or not cared about. It just means that something affects this brain process.

Facial Recognition and CVI

Reduced Visual Acuity

SIGHT-SIM www.sight-sim.co.uk

This images (above) has been simulated to show how reduced visual acuity affects what a face looks like. The left image is typical (6/6 or 20/20 or LogMAR 0.10) vision. The middle image is 6/36 (20/120 or LogMAR 0.8), and the right image is 6/96 (20/230 LogMAR 1.2).

SIGHT-SIM www.sight-sim.co.uk

These images are of the same person, with the second and third images degraded to show what they look like with levels of reduced visual acuities that are not uncommon in children with CVI.

You might be able to tell it is the same person from the two unedited images, but can you tell it is the same person from these images (below)?

SIGHT-SIM www.sight-sim.co.uk

These two pictures, also with simulated reduced visual acuities, are of the same person viewed from different angles under different lighting conditions, with different hairstyles, facial expressions, and in different locations. The images above shows what people may look like with reduced visual acuity at these level (6/96 or 20/230) which can be present from birth. So it's not surprising that face recognition can be difficult.

Reduced Contrast Sensitivity

SIGHT-SIM www.sight-sim.co.uk

These images above show how reducing levels of contrast sensitivity affect what a face looks like. The visual acuity (clarity) on these images has not been altered, but the contrast of the two pictures (middle and right) has been reduced.

When a person with CVI is affected by reduced visual acuity, they may well be affected by reduced contrast sensitivity as well, making faces even more difficult to identify.

Visual Field Impairments

If the whole, or a part of a person's face is not visible or is not fully visible due to a visual field impairment, this will make facial recognition more difficult, or impossible.

Simultanagnostic Vision

A mother sent us photos her daughter with simultanagnosia had taken of her own face, but the daughter took photos of bits rather than the whole, a bit like these, below, possibly thinking that this was how other people see...

We have explained why visual processing of the human face is complex. For some people with reduced simultanagnostic visual attention (lesson 7c) only a part of something may be seen. When they need to process something complicated, and a face is very complicated in terms of brain processing, this type of lack of visual attention can mean that only a small amount of the face, maybe just a single part, can be seen.

Think of the face store in the mind (in the right temporal lobe). Imagine what the face pictures in that store might look like, when only parts have been seen at any one time? And this does not only apply to the faces of other people, it also applies to their own face in the mirror, only part of which may be seen at any one time.

Temporal Lobe Issues

Where there has been damage to the right temporal lobe, the capacity of the 'face-store' may be limited, reduced, inconsistent or even absent.

If a face is not in the face-store, for any reason, including the complete absence of a face-store, then you could see someone you know extremely well, yet facially they will always be a unrecognisable, like a stranger.

Targeted support

Here the Targeted Support becomes a bit tricky, because the same difficulty (recognising people by their faces) can have many different causes. In some, it means the approaches to support the person will be different.

Reduced Visual Acuity

Typically, if something is too small to be seen clearly, the obvious solution is to make it bigger or to get closer. However, with the human face (of a real person in front of you) we are of course limited to the size their face is.

Remember that while facial recognition is a very convenient way of recognising people, it is the person we want to recognise, so think of different ways you can help the person, including:

  • If you wear spectacles, get a pair with a thick bold coloured frame.
  • Wear consistent make-up, maybe a bright lipstick.
  • Think of the clothes you wear, maybe a scarf, tie or shirt of the same colour (but not patterned).
  • When out and about, a well known coloured hat, scarf or anorak can be seen and identified from any direction
  • Use the person's other senses to help, maybe wear the same perfume / cologne.
  • Plan where you will be when meeting the person.
  • Approach the person by verbally introducing yourself.
  • Teach what a person's footfall sounds like

All of these approaches are only useful if they are applied consistently, and whilst not 100% efficient, they do help. Visual acuity can improve, particularly in the very early years, but remember the child may be learning to recognise people only when older, so we recommend finding different ways to help someone recognise a person for those where their visual acuity is or has been too reduced, to clearly and consistently recognise people.

Reduced Contrast Sensitivity

Our advice is similar to that for those with reduced visual acuity (above). The addition of a bold striking colour (e.g. a bright red scarf or tie worn around the neck so it is close to the face) can be particularly helpful, but only if worn consistently.

Visual Field Impairments

A person will never be able to recognise a face, or anything, in a part of their visual field where they have no vision.

The person with a visual field impairment is often unaware of their absent visual field, so if you are standing, for example of the left side of someone with left hemianopia, you might as well be standing behind them - so don't blame them for not seeing you!

Learn the area of the visual field the person sees in, and approach them from that side so they can clearly see you.

Be careful not to approach people from a side where their vision is absent, as this can be frightening.

Simultanagnostic Vision

When possible, make sure there is no clutter or pattern behind you when approaching someone with simultanagnostic vision. Avoid anything that makes your face more complicated, like very decorative earnings or a patterned headscarf.

There are approaches that can be learnt, to build up a bigger more complex picture by putting smaller parts together, a bit like a jigsaw. The 'parts' are remembered, so form visual memories, and they ideally need to become connected, to form more complex visual memories.

A person with simultanagnostic vision may have an excellent capacity for visual memory, including faces. The problem is getting all the necessary visual information for facial recognition to the face store in the first place.

The 'jigsaw' image in the mind might not be perfect, but all it needs is to be good enough to recognise people. It requires practice, which is best with someone well known, with whom a lot of time is spent.

Temporal Lobe Issues

If the visual memory of the face is not in the mind, then that face can't be recognised, so alternative ways of recognising people are required. This can include:

  • Arranging to meet people in specific places.
  • Alternative way of identification such as consistently wearing specific items of clothing
  • Introducing yourself verbally
  • You may also be recognised by characteristic movements as you walk, or by the sound of your footfall (which are worth highlighting as ideas for the affected person themselves)

For all of the above:

For the affected person, learning to accept this not a fault, just something their brain does differently, and learning and gaining the confidence to tell people. To own these difficulties and explain that if someone is ever ignored it is not deliberate, and to come and say hello, can be very empowering. In a younger child, the subject is well worth teaching to their school class.

Visual Behaviours

Many affected people are often not aware, especially when young, and cannot know what they are not seeing. In addition to not recognising people, over time their different vision will inevitably lead to difficult situations. The resulting visual behaviours are likely for many, to result from a mixture of not recognising people, combined with a need to avoid uncomfortable situations where their challenges recognising faces have led to difficulties. This can lead to...

  • Avoiding certain social situations, particularly where there are a lot of people
  • Preferring small groups of known trusted people
  • Missing / Ignoring people
  • Mistaking one person for another
  • Not being able to find people

Self Referencing

For those of us unaffected by difficulties recognising faces, just try for a minute to imagine life where you could not recognise people by their faces.

Imagine a single day where everyone, yourself included, wore an identical mask, so no one could be facially recognised. Try to think about different ways it would affect you, and how you might get around it, and where it would cause you real problems.

Then imagine what it must be like, when you see everyone in a mask, but everyone else sees faces. What sort of disadvantages would you face, compared to everyone else.

And then imagine, that you are not even aware you essentially see people in a mask, you have never experienced life any other way, so you don't realise everyone doesn't see like you. So you not only have a condition that puts you at a considerable disadvantage, but you may not even be aware of it.

When others are not aware of it too, then they may give an incorrect diagnostic label to the resulting behaviours.

And here we start to explore how truly hidden a disability CVI is, hidden even to the affected person, to those closest to them including family, friends, colleagues and teachers.

You need to learn that not being recognised is not the same as not being known, liked or loved even.

Not being recognised facially is a brain process that has not worked effectively, for many possible reasons, none of which the owner of the brain has any conscious control over -

SO DON'T TAKE IT PERSONALLY!

UNDERSTAND AND ADAPT.

Checklist

Before moving on, please check that you have understood the following:

  • The purpose of recognising faces
  • Why recognising faces is such a complicated brain process
  • Where in the brain the mind's store of faces is located.
  • The name of the pathway from the occipital to the frontal lobes, via the temporal lobes.
  • The different ways different CVIs affect facial recognition
  • The different approaches needed to match the different CVIs.

Next lesson: Level 8c CVIs Ventral - Impaired Recognition of Facial Expressions

Further reading is not required to move on to the next lesson, but if interested you might find the following enjoyable:

Katherine's Playground CVI Pathway - Profile of a girl who did not recognise her mother on the school playground.

3Z Approach - A more detailed explanation of the 'jigsaw' approach, called 'Zoom In, Zip Up, Zoom Out' to aid understanding by connecting small and individual elements, in the mind.

Facial Recognition Paper - providing a more detailed explanation of the processes.

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At CVI Scotland we are devoted to helping people understand cerebral visual impairments, and together working towards developing the understanding of this complex condition.