3g - Visual Attention

Posted by Helen St Clair Tracy in Level 3 - Introduction to the Visual Brain
Published: 07/03/2019, 12:08am | Updated: 13/03/2019, 3:22pm

Video Link: https://vimeo.com/323461027

To look at anything requires visual attention.

To see these words, and to read them, requires visual attention.

The things you are looking at you can see most clearly (right now, these words you are reading).

If your entire visual field was filled with words, just like these ones, you wouldn't be able to read them all clearly and easily, without changing where you are looking.

So think for a minute what it means to look at something.

You can see with your entire visual field, as we explained in lesson 3d, even seeing things that are slightly behind you under certain circumstances, but you can't see everything in your entire visual field clearly.

The things you can see most clearly are the things you are looking at.

Seeing is not the same as looking, and looking is not the same as seeing.

You look using your visual attention.

When you are looking for something, you are searching, that is visually searching, using your visual attention.

Where there is a lot of visual information to process, visual search becomes more difficult, slower and less accurate.

Have you ever gone to a supermarket you are not familiar with, and tried to find items, not knowing where things are kept. It's difficult and frustrating.

Where there is less visual information to process visual search is much easier, faster and more accurate.

But...just because you are not looking at something, does not mean everything else in your visual field isn't important.

Classrooms typically have pictures all over the walls

The pictures are a lovely celebration of hard work by children, but those pictures are making the children's brains work harder, processing the visual information in their peripheral vision, whilst they are trying to concentrate on the teacher.

But there's more... modern classrooms widely use technology, including interactive boards where superfast internet connections can mean not only is the visual information very detailed (making it harder, slower and less accurate to process), but, as is it moving and changing, making the demands on the brain harder still.

In terms of the optimal learning environment for our brain, it could be argued that Victorian classrooms, where the speed of teaching was dictated by how fast a teacher could write on a blackboard, and there was no clutter and natural light, was far better than the fast moving cluttered, often open plan technologically based classrooms of today.

Visual attention is processed in a part of the brain called the posterior parietal lobes (see lesson 1c).

Visual attention is processed in the posterior parietal lobes.Visual attention is processed in the posterior parietal lobes.

Visual attention can be reduced, making visual search more difficult, slower and less accurate, for many reasons, including:

  • When you are somewhere very cluttered, especially if it is somewhere unknown
  • If you are feeling unwell, tired, stressed , exhausted or very excited
  • If you are intoxicated from alcohol, some medications or drugs

These are all temporary reasons for reduced visual attention.

Additionally, visual attention can be reduced if the part of the frontal and / or the posterior parietal lobes have been permanently affected, which can happen due to:

  • Complications or brain developmental issues before, during or soon after birth, including premature birth
  • Brain injuries, at any time in life
  • Infections and diseased affecting the brain, at any time in life

Impaired visual search due to reduced visual attention, due to posterior parietal lobe injury is called simultanagnostic vision.

As with all visual challenges and behaviours, once lack of visual attention has been identified, it is important to understand why - what is the cause of the difficulty? Impaired visual search is not the cause of impaired visual search - something else is, maybe tiredness, intoxication or simultanagnostic vision.

It can be very difficult to tell if the challenges with visual search are simultanagnostic (due to posterior parietal lobe injury) or due to the attention from the frontal part of your brain (your control centre, as explained in lesson 1f), because they can look very similar. There are ways to tell the difference, and we will explain this in future lessons.

Simultanagnostic vision can be mild to severe, and can vary for the person, who at times may be able to see typically, and at other times may not be able to see at all.

Future lessons will be dedicated to simultanagnostic vision, which can remain unknown, even to the person who has it, and can cause:

  • Challenging and autistic behaviours
  • Difficulties with staying focused and being distracted
  • Difficulties reading and writing
  • Difficulties with coordination
  • Difficulties with social relationships and confidence
  • Difficulties with general learning and development
  • Difficulties with independent living skills and safety

The majority of people who have simultanagnostic vision have typical visual acuity, and so pass a standard vision test, and are not thought to have a visual impairment, and the challenges from the above lists are given other labels, including autism, ADHD, DCD/dyspraxia, dyslexia, learning delays and global developmental delays.


Before you move onto the next lesson, please check:

  • You understand the difference between visual attention and visual search, and how they are connected.
  • You understand the difference between seeing and looking, and how they are connected
  • You understand the conditions that make visual search more difficult, slow and inaccurate.
  • You know there are many different causes of reduced visual attention.
  • You know what simultanagnostic vision is, and that is can vary.

Next lesson: Level 3h An Introduction to the Visual Brain - Reflex Vision


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