Daily brain tests could reveal how prepared your immune system is to fight a future viral infection.
A study conducted by researchers from the University of Michigan (UM) showed that poor immune performance tends to go along with periods of fluctuating cognitive performance.
During the first few days of the eight-day study, three times a day, 18 participants tested their attention, reaction time and ability to switch between numbers and symbols. On the fourth day of the study, the group was deliberately exposed to human rhinovirus (HRV), which commonly causes the common cold.
During the remaining days, a nose wash was self-administered by the participants to measure the presence and volume of excreted viral cells.
The volunteers were also asked to rate their experience of eight symptoms, including chills, cough, headache, stuffy nose, runny nose, sneezing, sore throat and fatigue.
Ultimately, those who shed the most virus and had the worst symptoms tended to show inconsistent cognitive scores in the days leading up to their illness.
“At first, we didn’t find that cognitive function had a significant association with disease susceptibility because we used the raw scores,” says bioinformatics researcher Yaya Zhai at UM.
“But later, when we looked at changes over time, we found that variation in cognitive function is closely related to immunity and susceptibility.”
In other words, one single test is probably not enough to determine the state of a person’s immune system. A trend in cognitive performance measured over days, however, could be the ticket.
The study authors acknowledge that most people are unlikely to take a cognitive test three times a day for the rest of their lives. But their results still showed strength even when only five tests were taken into account. – as long as they started three days before infection and at least one test was performed per day.
In the real world, a person does not know when they will be exposed to a virus next. This means that for brain tests to predict future immune responses, they likely need to be taken semi-regularly. Regularity remains to be determined.
The current study is small and only suggests a possible link between cognitive function and a healthy immune system. Further research among larger cohorts is needed to verify the results.
In the past, scientists studying brain function and health have relied on raw cognitive scores. But emerging research suggests that the highs and lows of brain tests contain more information than any single test taken in isolation.
An impressive 19-year study, for example, found that when a person’s reaction times show greater variability on tests, that person is at greater risk for falls, neurodegenerative disorders, and death.
The authors of the current study hope that one day, brain tests can be easily accessed and tracked by the public using their own smartphones.
Information about an individual’s typing speed, typing accuracy and sleep time, for example, could be combined with tests of attention and memory to better predict when they are at increased risk for serious illness.
Precautionary measures could then be taken to reduce their exposure, or secure their body’s defences.
“Traditional clinical cognitive assessments that look at raw scores at a given time often don’t provide an accurate picture of brain health,” says neuroscientist P. Murali Doraiswamy of Duke University.
“At home, periodic cognitive monitoring, via digital self-testing platforms, is the future of brain health assessment.”
The study was published in Scientific reports.