Northwestern held steady at No. 4 in Lumosity’s annual rankings of the country’s smartest colleges.

NU trails Washington University in St. Louis, the Massachusetts Institute of Technology and Princeton University. Last year, it followed MIT, Harvard University and Stanford University.

Lumosity studied schools’ performance in five areas: memory, processing speed, flexibility, attention and problem solving. The organization found its own metrics highly correlated with ACT and SAT scores among students.

“We have billions of data points on cognitive performance, and this analysis is just one example of how we can use our database to uncover cognitive performance trends within a particular demographic and at a certain point in time,” said Dr. Daniel Sternberg, Lumosity’s data scientist, in a news release. “College rankings typically rely on standardized test scores and GPA — what’s unique about our college rankings is that we are able to measure a sample of a student population’s core cognitive abilities, which are important underlying factors that allow you to function in your everyday life.”

The University of Chicago came in at No. 6 on the list. The University of Michigan-Ann Arbor, at No. 44, was the only other Big Ten school to crack the top 50.

— Joseph Diebold