Daily Intelligencer Published: Dec. 16, 2016, by Jeff Wise
To ascertain whether adrenaline made their brains speed up, the scientists had invented a wrist-mounted device they called the “perceptual chronometer.” The LED display shows pairs of numbers. If the numbers are set to change more quickly than a person’s mind can perceive, he or she will see only a blur. The scientists set the perceptual chronometer’s flicker rate just beyond what their subjects could perceive when calm. If the intense fear of free fall ramped up the subjects’ perception rate, they should be able to discern the numbers.