Lost under stress? Study shows cortisol can scramble the brain's internal map

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.