Stress hormones disrupt the internal GPS system of the brain

Persons under stress may have a harder time spatially orienting themselves. Researchers in Bochum have discovered why.

The stress hormone cortisol disrupts the brain's navigational system. It impairs the function of the grid cells that play a crucial role in orientation. This has been verified by researchers from Ruhr University Bochum, Germany, in an imaging study with 40 individuals. The participants completed a virtual navigation experiment while their brain activity was recorded in an MRI scanner. If the subjects had received cortisol prior to the experiment, they performed more poorly and the exact activity pattern of the grid cells became indistinct. The results were published online in the journal PLOS Biology on March 12, 2026.

It is well known that stress influences human behavior and thinking, but it was mostly unclear how cortisol disrupts the circuits in the brain responsible for navigation. A team working with Dr. Osman Akan from the Ruhr University Bochum, Department of Cognitive Psychology, and colleagues from the Department of Neuropsychology, as well as researchers from University Hospital Hamburg-Eppendorf, set out to investigate this very question.

40 healthy men took part in the experiment, each on two different days. On one day, the subjects received 20 milligrams of cortisol; on the second day, they were given a placebo. On each day, they took an orientation test while their brain activity was recorded in the MRI scanner.