Vision problems can predict dementia 12 years before diagnosis

Our research was based on 8,623 healthy people in Norfolk, England, who were followed for many years. At the end of the study, 537 participants developed dementia, so we were able to find out what factors could precede this diagnosis.

At the beginning of the study, we asked participants to perform a visual sensitivity test. To take the test, they had to press a button as soon as they saw a triangle forming in a field of moving dots. People who would develop dementia were much slower to see this triangle on the screen than people who would remain without dementia.

Why does this happen?

Visual problems may be an early indicator of cognitive decline, as the toxic amyloid plaques associated with Alzheimer's disease may first affect areas of the brain associated with vision, with parts of the brain associated with memory damaged as the disease progresses. Therefore, vision tests may detect deficits earlier than memory tests.

there are many Other aspects Visual processing affected by Alzheimer's disease, such as the ability to see the surroundings of objects (contrast sensitivity) and distinguish between certain colors (the ability to see the blue and green spectrum is affected at the onset of dementia), and this can affect people's lives without them immediately realizing it.

last An early sign of Alzheimer's disease is a deficit in “inhibitory control” of eye movements, whereby distracting stimuli seem to capture attention more easily. People with Alzheimer's disease seem to have difficulty ignoring distracting stimuli, which can manifest as problems controlling eye movements.

If dementia makes it more difficult to avoid distracting stimuli, these problems may increase the risk of accidents. On the road – something we are currently investigating at Loughborough University.

Face recognition

we've got Some evidence Which suggests that people with dementia tend to process faces of new people ineffectively. In other words, they do not follow the usual pattern of examining the face of the person they are talking to.

In healthy people, this pattern would be from eyes to nose to mouth. We do this to “imprint” the face and remember it later. Sometimes people can tell when the person they're talking to isn't doing it.

In fact, some doctors who work with people with dementia will know that someone has dementia when they meet them. Sometimes, people with dementia may appear lost because they do not intentionally move their eyes to scan their surroundings, including the faces of people they have just met.

Therefore, later, you will be less able to recognize people because you did not record their characteristics. Therefore, this initial problem of not recognizing people we have just met may be related to ineffective eye movement to new faces and not simply a memory disturbance.

Can eye movement improve memory?

However, since visual sensitivity is linked to memory performance (even using non-visual tests), we are also testing whether having people make more eye movements helps improve memory. Previous research on this topic is diverse, but some… studies Found that eye movement can improve memory. Perhaps this explains why we find that people who… Watch more TV and read more They have better memory and a lower risk of dementia than those who do not watch.

When we watch television or read, our eyes move from one side of the page and the television screen to the other. However, people who read frequently also tend to have more time to study. Good education provides reserve capacity for the brain, so that when connections in the brain are damaged, the negative outcome is less.

In others studiesRapid left-to-right and right-to-left eye movements (two eye movements per second) have been found to improve autobiographical (life story) memory. However, some studies suggest that this beneficial effect of eye movement only benefits right-handed people. We don't know for sure why this happens.

Despite these exciting results, treating memory problems using intentional eye movements in older people has not been widely used. Furthermore, the use of eye movement deficits as a diagnosis is not a common source, despite the capabilities of eye movement technology.

One barrier may be access to eye-tracking technologies, which are expensive and require training to use and analyze. Until cheaper and easier-to-use eye trackers become available, it will not be possible to use eye movements as a diagnostic tool for early-stage Alzheimer's outside the laboratory.

* Eve Hogerforst He is a professor of psychobiology at Get the free photo pose and dozens of free wallpapers; Ahmed Beji He is a researcher in the field of neurological rehabilitation Get the free photo pose and dozens of free wallpapers; that it Tom Wilcoxon He is a professor of psychology at Get the free photo pose and dozens of free wallpapers This article has been republished from the site Conversation Under Creative Commons license. Read the article The original is here.