Lessons

11a - Palinopsia

Posted by Helen St Clair Tracy in Level 11 - Brain Disorders of Visual Processing
Published: 25/09/2021, 12:10am | Updated: 23/10/2021, 1:17pm

Please note, the images on this page and in the video tutorial are our interpretations from accounts shared with our team and further accounts and images available on-line.

Video Link: https://vimeo.com/589923546

The word palinopsia means to see something again, but what does that mean?

As we have explained in these lessons, the picture of what you are looking at right now is created in your mind involving many different processes from different parts of the brain, all coming together, so you can see clearly, know what you are looking at, and where what you are looking at is located, in relation to where you are.

There are other important processes in relation to your vision. One of those processes involves very quickly replacing the images in your mind with new images to reflect the changes in what you are looking at.

To explain, let us try a quick exercise.

Firstly, look at the picture of the cow. We have deliberately left a wide gap between the two images.

As you look at the picture of the cow, what you see, that is the image your mind creates, is an image of a cow.

Now look at the image on the right of the flowers. The chances are you can still see some of the cow in your peripheral vision to the left, but the image you were looking at of the cow has been replaced with the image of the flowers.

Let us think about that replacing process.

Firstly, the previous image needs to be discarded, otherwise, when you look at the flowers, you will still see the cow.

This exercise is limited because we can only show you images on a screen. Try the same exercise with two different things to your left and right in the area where you are now, starting with looking at something to your left, and then looking at something to your right, and note the image you were looking at (on the left) has been replaced with the image on your right.

This process of discarding and replacing is going on all the time, running in the background of your visual processing. It's a bit like a computer screen that automatically updates or refreshes as you are using it, checking for changes many times a second.

This discarding / replacing visual process is not only running all the time, it is also running in relation to everything in your visual field, not just what you are looking at. It is also running in relation to everything in your visual field when there is movement. As you move your head to look around you, you create movement of your mental imagery, so what you see is moving pretty much all the time, just by the movement you create.

To see this clearly, your mind is constantly accepting new images, and getting rid of the old ones.Video Link: https://vimeo.com/638092027

For most, this process is so efficient it ties everything together seamlessly, so you are not even aware it is going on.

But what might it be like if it was not working typically, and the images you have moved on from aren't discarded but are still there? This is what happens with palinopsia.

There seem to be three broad different groups of experiences with palinopsia.

  • 1. Full overlay: The last image looked at overlays and covers the next image you are trying to look at.
  • 2. Transparent overlay: The last image looked at overlays the new image you are trying to look at, but you can see both in the same place at the same time, so there is a degree of transparency.
  • 3. Trail: A kind of trailing effect, where the image of what you were looking at, rather than completely disappearing, visually trails, into disappearance.

So the issue is one of the previous image not being discarded from the mental visual imagery fast enough.

Thinking back to looking at our cow first, and then the flowers:

Full overlay - the previous image lingers to completely cover the new image.Full overlay - the previous image lingers to completely cover the new image.

Transparent overlay - the previous image lingers, but in a way that both images can be seen at the same time in the same place.Transparent overlay - the previous image lingers, but in a way that both images can be seen at the same time in the same place.

Trail - the 'disposal' of the old image may be delayed creating a sort of trail.Trail - the 'disposal' of the old image may be delayed creating a sort of trail.

This is a very simple explanation using two simple but clearly very different images.

Life of course is not that simple.

Let's imagine you are in this meeting.

The woman on the left with long blonde hair has just been talking so you were looking at her, but now you are looking at the paper she is pointing to.

How might that experience be different for someone with palinopsia?

The previous image of the woman may remain, and cover or partly cover the new image of the paper you are trying to look at, so you can't see the new image, or can't see all of the new image:

Full overlay - the previous image overlaps and covers the new image so you can't see it.Full overlay - the previous image overlaps and covers the new image so you can't see it.

Or, the previous image of the woman may remain, and cover or partly cover the new image of the paper you are trying to look at, in a way that you can see both the previous image and the new image at the same time in the same place.

Transparent overlay - the previous image overlaps the new image but is transparent, so you can see both at the same time, but one of the images, the previous one, is in the wrong place.Transparent overlay - the previous image overlaps the new image but is transparent, so you can see both at the same time, but one of the images, the previous one, is in the wrong place.

Or, the previous image trails:

Trail - the image of what you were looking at can trail across what you are now looking at.Trail - the image of what you were looking at can trail across what you are now looking at.

How long the effect lasts can vary from person to person, but even if just half a second, it can create considerable difficulties.

Palinopsia means:

  • Things may not be seen clearly or fully, and...
  • Things may not be in the correct place. This woman's head belongs with the rest of her body but has been moved to the top of the table, and...
  • Finding things must be extremely difficult, so palinopsia...
  • Can create confusion and even be scary.

The causes include a wide range of events, injuries and diseases that can affect the brain, including seizures, types of migraine, and certain medications.

Palinopsia can affect a person from birth and all their life, or be acquired, and can be mild, only occasionally affecting them, or severe, happening all the time.

Palinopsia & Visual Hallucinations

It is easy to see how palinopsia might be mistaken as a visual hallucination, when you can clearly see the decapitated head of your colleague on the table in front of you.

We explain visual hallucinations in the next lesson (11b). Both palinopsia and visual hallucinations, for different reasons, can mean things that are not there, are seen.

It can be very difficult to separate palinopsia from hallucinations and other experiences where something that is not there is seen, for example the visual 'auras' that sometimes accompany migraine headaches, seizures and following trauma to the head, and the effects of medications. It is also possible to have both palinopsia and any of these other experiences, co-occurring.

The visual auras associated with migraine are not palinopsia, although migraine is a known association with palinopsia.Video Link: https://vimeo.com/495465116

Things Palinopsia is Not

  • 1. Trails caused by things moving too fast.

When things move too fast to be seen clearly, what is seen is a sort of trail. This trail is an effect due to a lack of clarity because what you are looking at is moving too fast, explained in lesson 3e. The 'trail' is different to the trail some experience with palinopsia.

  • 2. After images

Do you remember a time a bright light has been turned on, or someone takes a photo of you with a flash, and the very bright light source stays in your vision sort of flashing, for anything from a few moments to several minutes? This is called an after-image. The image, for example of the bright filament even after you are no longer looking at the light, is visible. Whilst the image has been repeated, this is because part of the eye (the retina) has become overstimulated and needs a bit of time to recover. It is not palinopsia which is due to the brain and not limited to very bright stimulations.

When we see a very bright light source, we naturally look elsewhere, but the 'imprint' of that source, for example the very bright filament of the light, can remain visible for many seconds, even minutes later. This is called an after image and is different from palinopsia.When we see a very bright light source, we naturally look elsewhere, but the 'imprint' of that source, for example the very bright filament of the light, can remain visible for many seconds, even minutes later. This is called an after image and is different from palinopsia.

Targeted Support

If medications are causing the disturbances, then an alternative medicine may help.

If intermittent, learn the triggers for example a migraine, and have a plan, to ensure you are safe and secure until it passes.

If persistent, learn to use your other senses, and if it occurs with predictable patterns, see if you can learn to work with the rhythms of your palinopsia, which may involve sitting still for longer periods of time and looking at the same thing rather than looking around, even thinking with your eyes closed.

Checklist.

Before moving on, please check you have understood:

  • What palinopsia means.
  • The process of discarding and replacing the images of what you are looking at.
  • The three broad types of different experiences of palinopsia.
  • Why palinopsia can be confused with visual hallucinations.
  • The difficulties palinopsia creates.
  • Other conditions palinopsia might appear like, but is not.
  • Causes of palinopsia.
  • Suggestions to help with the effects of palinopsia.

Next lesson Level 11b Brain Disorders of Visual Processing, Visual Hallucinations

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