A simple computer test that combines thinking and movement can help detect heightened risk for developing Alzheimer's, even before there are any telltale behavioural signs of the disease, scientists say.
Researchers asked the participants to complete four increasingly demanding visual-spatial and cognitive-motor tasks, on dual screen laptop computers.
The test aimed at detecting the tendency for Alzheimer's in those who were having cognitive difficulty even though they were not showing outward signs of the disease.
"We included a task which involved moving a computer mouse in the opposite direction of a visual target on the screen, requiring the person's brain to think before and during their hand movements," said Professor Lauren Sergio in the School of Kinesiology & Health Science at York University.
"This is where we found the most pronounced difference between those with mild cognitive impairment (MCI) and family history group and the two control groups," said Sergio.
"We know that really well-learned, stereotyped motor behaviours are preserved until very late in Alzheimer's disease," said PhD candidate Kara Hawkins who led the study.
These include routine movements, such as walking. The disruption in communication will be evident when movements require the person to think about what it is they are trying to do.
For the test, the participants were divided into three groups - those diagnosed with MCI or had a family history of Alzheimer's disease, and two control groups, young adults and older adults, without a family history of the disease.
The study found that 81.8 per cent of the participants that had a family history of Alzheimer's disease and those with MCI displayed difficulties on the most cognitively demanding visual motor task.
"The brain's ability to take in visual and sensory information and transform that into physical movements requires communication between the parietal area at the back of the brain and the frontal regions," said Sergio.
"The impairments observed in the participants at increased risk of Alzheimer's disease may reflect inherent brain alteration or early neuropathology, which is disrupting reciprocal brain communication between hippocampal, parietal and frontal brain regions," Sergio said.
"In terms of being able to categorise the low Alzheimer's disease risk and the high Alzheimer's disease risk, we were able to do that quite well using these kinematic measures," said PhD candidate Kara Hawkins who led the study.
"This group had slower reaction time and movement time, as well as less accuracy and precision in their movements," said Hawkins.
The study was published in the Journal of Alzheimer's Disease.
