A decline in navigational skills could predict neurodegenerative disease

August 30, 2017
Diagram of the brain of a person with Alzheimer's Disease. Credit: Wikipedia/public domain.

Changes in how humans map their surroundings and construct and follow directions as they age have been understudied compared to effects on memory and learning. However, age-related declines in navigational ability are independent of those more well-known cognitive downturns, and could form the basis for tools for the early diagnosis of Alzheimer's disease. Researchers discuss this possibility in a review published August 30 in the journal Neuron.

"In humans, navigation is much more cumbersome to research than learning or memory," says Thomas Wolbers, a neuroscientist specializing in aging and cognition at the German Center for Neurodegenerative Diseases. "But it has such a dramatic impact on everyday life, and the key structures of the 'navigational network' in the brain are very sensitive to both ordinary healthy aging and pathological factors."

Currently, Alzheimer's disease is diagnosed based on an individual's medical history, , and performance on tests that measure memory, language, and reasoning impairments. Wolbers and his colleagues from the United States and the United Kingdom suggest that navigational impairments are among the earliest signs of the Alzheimer's progression. Healthy older individuals, for instance, strongly prefer to map objects and landmarks relative to their body position (an egocentric strategy) rather than in relation to external objects such as global landmarks or boundaries (an allocentric strategy). This strategic bias makes it much more difficult for them to learn the spatial layout of an environment and can thus reduce their mobility, a worrisome sign in younger people.

"It can take up to 10 years after the onset of Alzheimer's for someone to show abnormal results on the standard cognitive tests that are available today, and that's 10 years that you've lost for treating it, should an effective therapy come along down the road," says Wolbers. "This is where navigation-based diagnostics could contribute, by reducing that window."

Navigational testing is held back by a pair of obstacles, though both are receding. The first is the lack of standard tests for navigational tasks and population norms with which to evaluate results. More-affordable and portable virtual reality technology is making standardized test conditions possible, however, while co-author Jan Wiener of the United Kingdom's Bournemouth University is one of the scientists behind the mobile app Sea Hero Quest, a game designed to collect population data on navigation decisions for dementia research.

The second holdup is that navigational abilities vary wildly from person to person, more so than for memory or other cognitive functions, Wolbers says. An effective diagnostic tool might need to be longitudinal, tracking an individual's navigation behaviors at different points in time throughout their life and looking for signs of early or accelerated decline. "We need longitudinal human data to be able to definitively say whether a change in navigational function can be used to predict whether Alzheimer's or any other neurodegenerative disease will develop later on," Wolbers says.

With such data and the improved virtual reality setups, the researchers conclude that a navigational test battery analogous to those used for memory and learning will be feasible. For now, Wolbers suggests that people train and use the hardwired into their brains, especially in an age of commonplace in-car and handheld GPS technology.

"There is growing evidence that if you rely too much on that technology it can have a detrimental effect on your navigational ability and in the long term may even be a risk to develop pathological conditions," he says.

Explore further: Scientists launch virtual reality game to detect Alzheimer's

More information: "The Aging Navigational System," Neuron (2017). DOI: 10.1016/j.neuron.2017.06.037

Related Stories

Scientists launch virtual reality game to detect Alzheimer's

August 29, 2017
Sea Quest Hero is more than just the usual computer game in which players find their way through mazes, shoot and chase creatures—it also doubles as scientists' latest tool for studying Alzheimer's disease.

Navigation skill test could diagnose Alzheimer's long before memory fails

April 20, 2016
Long before Alzheimer's disease can be diagnosed clinically, increasing difficulties building cognitive maps of new surroundings may herald the eventual clinical onset of the disorder, finds new research from Washington University ...

Study finds strategy shift with age can lead to navigational difficulties

February 6, 2012
A Wayne State University researcher believes studying people's ability to find their way around may help explain why loss of mental capacity occurs with age.

Problems finding your way around may be earliest sign of Alzheimer's disease

April 21, 2016
Long before Alzheimer's disease can be diagnosed clinically, increasing difficulties building cognitive maps of new surroundings may herald the eventual clinical onset of the disorder, finds new research from Washington University ...

In Alzheimer's, excess tau protein damages brain's GPS

January 19, 2017
Columbia University Medical Center (CUMC) researchers have discovered that the spatial disorientation that leads to wandering in many Alzheimer's disease patients is caused by the accumulation of tau protein in navigational ...

Machine learning can predict rate of memory change

July 31, 2017
In new research published today, researchers have created a machine learning algorithm that is able to form two distinct groups of people who have early memory problems known as mild cognitive impairment. The algorithm was ...

Recommended for you

Is the Alzheimer's gene the ring leader or the sidekick?

September 15, 2017
The notorious genetic marker of Alzheimer's disease and other forms of dementia, ApoE4, may not be a lone wolf.

Potential noninvasive test for Alzheimer's disease

September 6, 2017
In the largest and most conclusive study of its kind, researchers have analysed blood samples to create a novel and non-invasive way of helping to diagnose Alzheimer's disease and distinguishing between different types of ...

Researchers unlock the molecular origins of Alzheimer's disease

September 6, 2017
A "twist of fate" that is minuscule even on the molecular level may cause the development of Alzheimer's disease, VCU researchers have found.

Is dementia declining among older Americans?

September 5, 2017
(HealthDay)—Here's some good news for America's seniors: The rates of Alzheimer's and other forms of dementia have dropped significantly over the last decade or so, a new study shows.

Which genetic marker is the ring leader in the onset of Alzheimer's disease?

September 4, 2017
The notorious genetic marker of Alzheimer's disease and other forms of dementia, ApoE4, may not be a lone wolf.

A decline in navigational skills could predict neurodegenerative disease

August 30, 2017
Changes in how humans map their surroundings and construct and follow directions as they age have been understudied compared to effects on memory and learning. However, age-related declines in navigational ability are independent ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.