9e - Parallel Processing

Posted by Helen St Clair Tracy in Level 9 - Dorsal (2)
Published: 08/09/2021, 12:46am | Updated: 25/09/2021, 8:44am

The lessons in this level (Level 9) have been written from many first-hand accounts shared by people who look after children who have a type of CVI where their posterior parietal lobes have been affected. This is therefore more subjective than our other lessons, but it is the subject of ongoing research. As the accounts have been so consistent, we wanted to share them, because the understanding they give us lets us make simple adjustments to help many people, especially those unable to communicate their challenges, as is the case for young children and those with limited communication skills.

Video Link: https://vimeo.com/589914113

Think of a busy supermarket....

Imagine there are ten checkouts (tills).

Each checkout can serve ten people an hour.

10 Checkouts X 10 Customers per hour = 100 Customers per hour

So, if all checkouts are open, one hundred customers per hour can put their shopping through the checkout and pay for it and leave.

But what happens if:

  • Not all the checkouts are open?
  • There are more than a hundred people an hour trying to get through?
  • Some of the checkouts are not working properly?
  • A checkout operator is new and a bit slower than everyone else.

Very simply, problems happen. Everything slows down, queues build, people get irritated, stressed, even angry. Mistakes are made, things are rushed.

Thinking of the checkouts, look at the images in the 14 second video clip below. The brain on the left is typical, called 'control'. Think of it as representing the supermarket with all ten checkouts open and working. The brain on the right has CVI. Pause the video at 10 seconds and think about the checkouts. Compared to the typical (control) brain, the CVI brain only has one or two checkouts open and working compared to ten.

The Laboratory for Visual Neuroplasticity, Harvard Medical SchoolVideo Link: https://vimeo.com/221750541

Going back to our problems in the supermarket, the checkouts represent the parallel processing capacity of the brain. Say ten checkouts constantly processing 10 customers at a time (in parallel) is optimal for a typical brain, then what about the person with CVI who can process only 5? What difficulties might there be when...

  • Not all the checkouts are open. With reduced parallel processing, the brain can't cope with as much, and incoming information, including sights and sounds, can be overwhelming. An example may be a child with CVI who can work well at home in their quiet clear bedroom, but not in a classroom, because there is too much incoming information from the other children, noise and clutter in a classroom. For a mildly affected child, it may mean they become tired a little easier than other children, or are a bit 'frazzled' at the end of the day and need to rest when home. For more severely affected children, they can only slowly process one thing at a time, perhaps more slowly too...one checkout, one customer, taking as long as it takes.
  • There are more than a hundred people an hour trying to get through. This relates to too much incoming information to cope with. Many people with CVI need uncluttered quiet places to feel comfortable and concentrate. Busy places can make the mildly affected a little irritable, but can be completely overwhelming or even terrifying for the more severely affected.
  • Some of the checkouts are not working properly. In lesson 9c we discussed the visual map creating dynamic challenges. This map, affecting both what you see and hear (lesson 9d) feeds the conscious part of your brain (lessons 1f and 3k). This can mean the awareness of the person with CVI in relation to what they see and hear can be extremely dynamic. When also overwhelmed, this can create enormous challenges affecting every element of life for some.
  • A checkout operator is new and a bit slower than everyone else. The person with CVI has a very complex condition, and rather than seeing them as 'slow' see them as extraordinary, because they are having to work extremely hard to make sense of a world that most take for granted (see Self Referencing, below). They are doing the equivalent of trying to process a hundred customers an hour with maybe only one checkout, which can be very glitchy, and they are tired, so things can take longer. Allow time... as much time as is needed, and observe the incredible effort needed to achieve what they do.

Level 9 Extended Summary, Lessons 9d & 9e.

We have added two extra lessons to Level 9 because the auditory and parallel processing challenges described in this lesson and the previous lesson 9d, have been repeatedly described, although it is an area that requires further research.

In lesson 9c, in relation to the dynamic visual map, we noted:

What would appear to be happening, from the descriptions we've heard, is that as the demands of the (posterior parietal) mapping systems increase beyond their limited capacity (due to fewer fibres), the smaller central ones still work, while the larger outer ones become unavailable for use. This leads to the experience of less and less peripheral visual information being available to the mind to 'see', to the point where a person can quickly become practically unable to see or hear anything meaningful.

Lesson 9c

The video of the two brains we have featured on this page shows these fewer fibres. The link below, under Further Reading, has more information with links to a more detailed explanation.

Targeted Support

Each person is affected differently, but for many with CVI, parallel processing will be affected to some degree. Firstly you need to get a sense of how severely a person is affected.

For those more able academically, it does not follow that they are less severely affected.

Some may need a few breaks to rest and periods of quiet. Others, particularly with Balint Syndrome (lesson 7b) may need a very specific single sensory input environment, like a therapy tent, and learn only one thing at a time very slowly, but with tremendous effort.

The most severely affected children may benefit from a single sensory environment like a tent where everything is one colour.The most severely affected children may benefit from a single sensory environment like a tent where everything is one colour.

  • Reduce complexity and understand when and where environments can be challenging and plan accordingly.
  • Plan for breaks, and access to somewhere quiet and calm.
  • Remember people are amongst the most complex things to process, lesson 8b.

Visual Behaviours

  • Can become overwhelmed, upset, stressed or frightened
  • Can become tired and lethargic
  • May miss things
  • May need more time to do things
  • May find the same task easy in some environments, but difficult in others. Examples may include ease of working at home, but not in a class or a busy office. Another is enjoying socialising with a few known people somewhere quiet, but not with many people in busy places.

Self Referencing

Compared to how you can do things, a person with reduced parallel processing due to CVI may sometimes seem slow, or be irritatingly inconsistent, or even look learning delayed.

Look instead at the incredible amount they are doing, and how much harder they have to work, compared to you. Then, think what you can do to help (see Targeted Support, above).


Before you move on to the next lesson please check you understand the following:

  • What the term parallel processing, in relation to the brain, means.
  • That CVI commonly means reduced parallel processing, but can vary considerably from person to person.
  • What reduced parallel processing affects.
  • Ways to help people affected by reduced parallel processing due to CVI.

Next Lesson Level 10a Temporal Lobe - Prosopagnosia

Further Reading is not required to move on to the next lesson, but in interested you may find the following enjoyable:

Gordon Dutton's Blog 18 Using the example of airport security channels as a metaphor for the parallel processes.

3D Rotating CVI Brain Pathways More information about the rotating brains featured in the lesson.

Balint Syndrome

Level 9 Full Checklist

You should understand, in relation to 'the map' as described in these lessons...

  • The part of the brain the map is processed in
  • What a voxel is, as different from a pixel
  • What the map is
  • Things the map enables you to do
  • What the map may affect in terms of other processes
  • Ways the map keeps you safe
  • The map is body centric
  • What we mean when we use the term fibre
  • With CVI the map may have fewer, so bigger voxels
  • What bigger voxels entail in terms of causing difficulties with accurate movement using visual guidance
  • What bigger voxels mean in terms of looking at something or for something
  • The CVI Map, Voxels and Voxel Sliding Scale are all just illustrations to help understand the map created in the posterior parietal lobes to aid guidance of reach.
  • The CVI Map is dynamic
  • What happens when voxels get bigger and smaller.
  • The CVI Map is affected by the environment and how a person is feeling, and can be supported by memories and other senses.
  • The difference where a person feels anxious / stressed etc if they have a typical map compared with a CVI Map
  • Which part of the brain the sound map is processed in.
  • Why children with CVI may also have issues with the sound map.
  • The way sound is processed in the correct order - map, attention, recognition, and meaning.
  • Complications due to the sound map not being processed typically.
  • The challenges of both the sound map and the visual map not processing typically at the same time.

Congratulations on completing level 9!Congratulations on completing level 9!


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