Alzheimer is a neurodegenerative disorder that causes the brain to shrink and brain cells to die. It damages a person’s ability to think, remember, and affects the ability of basic functions.
According to the NIH, Alzheimer’s affects approximately 5.5 million US citizens and the age of the patients are 65 or more than that. And it is estimated to be as high as 24 million worldwide. This progressive disease will develop severe memory impairment in patients and they can lose the ability to carry out everyday's tasks. Damage from this neurobiological disease is totally irreversible. However, early detection can play a great role to slow its progression.
Recently, rsearchers have developed a simple behavioral test to detect or measure an individual’s risk of developing Alzheimer’s disease before symptoms appear. A team from CalTech and the Huntington Medical Research Institutes has work to develop a behavioral test.
The study involved 40 people with an average age of 75 and all are supposed to be healthy, who undergo many tests related to Alzheimer’s risk such as genome sequencing, MRI of the brain and the aforementioned invasive spinal fluid measurements. From these biomarkers peoples are categorized as high risk or low risk. The research aimed to develop a behavioral test whose results would correlate with these biological measurements and detect behavioral abnormalities long before any onset of symptoms in a less invasive way than measuring spinal fluid.
They developed a task with reputed "Stroop Paradigm Test". In which they use color words printed in different colors of ink, then participants are asked to name the color of ink that each word is printed in or read the word. The secret element of this test is, right before the actual target is shown, a colorless word is flashed rapidly on the screen, so rapidly that a participant cannot detect it consciously and It takes a bit of extra mental effort.
Moreover, the study tested the hypothesis that high-risk and low-risk cognitive healthy participants would be distracted by an unseen word differently.
The test showed that the person with high-risk biological factors slowed down by about 4 percent on the Stroop test when an unconscious and inconsistent word was flashed.
Member of the research group Hung says, ''the conditions that lead to Alzheimer’s may affect implicit cognition far before conscious cognition."
The researchers accentuate that this test is not diagnostic yet and this particular test cannot measure a persons risk for Alzheimer’s. But this test shows a correlation between the group of high risk individuals. To make it more predictive the next steps of the research is to combine the test with other non-invasive physical measurements such as neurophysiological markers, heart rate etc.
Original Research:
“Stronger implicit interference in cognitively healthy older participants with higher risk of Alzheimer’s disease” by Shao‐Min Hung et al. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring