A simple computer test can detect cognitive impairment years before the onset of Alzheimer's disease.

According to researchers at the York University, a test that combines movement and thinking can help catch Alzheimer's disease at an early stage.

Alzheimer's disease is the most common type of dementia. It affects people's memory and thinking abilities. The disease affects as many as 5.1 million Americans.

In the current study, the researchers show that a simple test can predict the onset of AD in people who haven't shown any outward symptom of the disease. Early diagnosis could lead to better treatment options.

The participants were given the test on a dual-screen laptop. The study is published in the Journal of Alzheimer's 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 Lauren Sergio, one of the study authors. "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."

For the study, the participants were divided into  three groups: one group had people with cognitive impairment or a  family history of AD, while the other two groups had healthy adults with no known history of cognitive problems.

The researchers found that  81.8 percent of the participants that had a family history of AD and those with MCI had problems finishing visual motor tasks.

"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," explained Sergio in a news release. "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."

The researchers maintain that the tests don't predict AD but, do catch some early signs of the disease.