Research results show that dementia can be predicted 12 years in advance, clue lies in visual processing speed



Previous research has shown that the risk of developing dementia in the future can be predicted from cognitive functions such as

vision and hearing . It has now been newly discovered that the efficiency of processing visual images is a strong predictor of dementia.

How your vision can predict dementia 12 years before it is diagnosed – new study
https://theconversation.com/how-your-vision-can-predict-dementia-12-years-before-it-is-diagnosed-new-study-226356

The relationship between dementia and vision
In a paper published in February 2024, a research team led by Ahmet Begde of Loughborough University in the UK showed that measuring visual sensitivity can predict dementia 12 years before diagnosis.

The study involved visual sensitivity tests on 8,623 participants from the EPIC-Norfolk prospective population cohort study, which tracked the health of people living around Norwich, a city in eastern England, for more than 25 years.

The study involved participants being asked to press a button as soon as they saw a triangle appear among a screen of moving dots. Of the 8,623 participants, 537 were later diagnosed with dementia, and it turned out that people who went on to have dementia had a harder time finding the triangle.



According to Begde and his team, the smudge-like 'amyloid plaques' found in the brains of people with Alzheimer's may have a detrimental effect on areas of the brain related to vision before damaging areas related to memory, so it is hoped that eye tests could detect signs of Alzheimer's before memory tests.

There is a range of visual abilities, but Alzheimer's affects the ability to distinguish the contours of objects - '

contrast sensitivity ' - and the ability to see certain colours such as blue-green.

Recent research has also shown that Alzheimer's patients are prone to 'saccadic eye movements,' in which the eyes move suddenly in response to distracting stimuli. In Alzheimer's disease, the ability to 'inhibitory control' to ignore stimuli is reduced, and this may manifest as a problem in controlling eye movements.

These dementia problems that lead to distraction are also thought to increase the risk of road accidents, and a research team from Loughborough University is investigating this.

◆ It also affects the ability to recognize people's faces
Studies suggest that people with dementia process new faces less efficiently -- in other words, their eyes scan faces differently than normal people.



Healthy people look at the other person's face in the order of eyes, nose, and mouth. This is a sequence that helps them remember the other person's face, and the other person can tell if the person in front of them is looking at them in this order.

On the other hand, people with dementia tend to have wandering eyes because they do not intentionally move their eyes to observe the environment, such as the face of a person they meet for the first time. Some doctors who often treat people with dementia are said to be able to tell whether or not a person has dementia just by meeting them face to face.

Dementia patients have difficulty recognizing people later because they are unable to properly recognize their facial features. In other words, 'the early symptom of dementia, the inability to remember people's faces, may be more a result of problems with eye movements to faces than a simple memory disorder,' Begde and his colleagues pointed out.

Eye movements may improve memory
Begde and his team believe that if visual sensitivity is related to memory, then eye movement training may be able to improve memory. Previous studies on this issue have had mixed results, but

some have shown that eye movements improve memory, and some have shown that people who watch a lot of TV or read a lot have better memory and a lower risk of dementia than those who don't.

When reading or watching television, our eyes frequently move back and forth between the paper or screen. Also, people who are accustomed to reading tend to have a longer education, which also leads to brain reserve, which helps minimize the negative effects of disconnection in one part of the brain.



Previous research has also shown that rapid left-right eye movements improve autobiographical memory , which is the ability to remember things about one's life.

Despite these discoveries, these findings have not yet been applied to the diagnosis of memory disorders, and eye movement therapy for memory disorders is not common. The bottleneck is the cost and training required to introduce eye tracking technology.

Therefore, Begde et al. said, 'We will need to wait for the advent of cheaper, easier-to-use eye trackers before tools to diagnose early Alzheimer's disease using eye movements become widespread.'

in Science, Posted by log1l_ks