For Black patients, historically rooted racial discrimination still affects the way intelligence and cognitive function is measured.
In the past decade, medical institutions practicing within the field of neuroscience have begun to reckon with their racist past — a necessary step for improving diagnostic cognitive tests for Alzheimer’s and related dementias. Many of these tests incorporate “race-norming” adjustments to test scores. The big problem is, race-norming adjustments aren’t based on evidence — they are based on historically ingrained prejudice.
Dr. Darshali Vyas, a clinical fellow at Massachusetts General Hospital researches the integration of racial biases in algorithms used to predict health outcomes and diagnose disease.
“By embedding race into the basic data and decisions of health care, these algorithms propagate race-based medicine,” Vyas and colleagues wrote in the New England Journal of Medicine in 2020.
While age and years of education are commonly adjusted for in these cognitive tests, they can’t account for early-life segregation in education, quality of education or discrimination, according to Lisa Barnes, professor at Rush Medical College.
That makes it difficult to untangle whether lower scores are a result of cognitive impairment or are simply artifacts of cultural forces related to racism or policies that promoted discrimination.
As a result, many of the cognitive tests that serve as the gold standard for diagnosing dementia are fundamentally flawed. And these problems aren’t new: According to historians and scholars, race-based adjustments originated as far back as the 15th and 16th centuries.
Since the 19th century, some psychologists and politicians have supported racist and eugenic policies through IQ tests, suggesting, for example, that enslaved people were less intelligent than their white owners. The underlying presence of these beliefs in cognitive science quietly strengthened the idea that there were genetically distinct races, and as a result, employment aptitude tests and cognitive tests were later adjusted based on race, under the assumption that Black people would score lower. This is called race-norming. Because of these inherently skewed designs, today, people with European ancestry who generally have increased access to resources and education still perform better than Black people on these gold-standard diagnostic tools.
As a result, Barnes says, researchers need to better contextualize these test scores and gather more data on race-based cognitive health biomarkers if they have any hope of accurately measuring cognitive health in Black individuals. Without taking these steps, the current set of diagnostic tests are not effective at setting objective cognitive health benchmarks to compare different racial groups to one another.
“A prevailing notion in the field is that African American individuals have a two to three times higher incidence of [Alzheimer’s] than white individuals,” she wrote. “Although the burden of dementia is certainly high in the African American population, inconsistencies in the existing data and an important lack of data where it is most needed mean that we cannot be confident that the evidence supports this claim.”
These adjustments were highlighted earlier last year when 20,000 former professional football players sued the National Football League (NFL) on the basis that race-norming impacted their cognitive diagnosis and treatment, allowing the NFL to withhold compensation.
“Black former players are automatically assumed (through a statistical manipulation called ‘race-norming’) to have started with worse cognitive functioning than white former players,” the lawsuit reads. “As a result, if a Black former player and a white former player receive the exact same raw scores on a battery of tests designed to measure their current cognitive functioning, the Black player is presumed to have suffered less impairment, and he is therefore less likely to qualify for compensation.”
There are steps researchers can take to help address these problems, Barnes told Being Patient. Those include better contextualizing a person’s test score, and tailoring cognitive tests to race and ethnicity. Beyond neuropsychological testing, she added, biomarker studies with racially and ethnically diverse participant groups are essential to understanding how Alzheimer’s manifests in different populations.
While it isn’t a welcome thought, it is important to consider the history of racism and eugenics which has shaped aspects of medicine, impacting the way cognitive function is measured.