It's far older than the 90s, but that's a product largely of what old papers have been digitized, and minorly on the terminology—I think you'll find some papers that say 'cognitive workload.'
I recently fixed up an old bit of scientific apparatus, which was used to measure the cognitive workload of various aircraft cockpit designs. It used a method called visual occlusion, which you can guess the rest of—the pilots would sit in trainers with a set of glasses, that had spring-loaded solenoid flaps to block the pilots' vision selectively. The open time as well as the frequency of the system was experimentally varied until the pilot could fly the plane safely, for given conditions. The vacuum tube circuit that I repaired had a date stamp from the mid seventies but this technique was already more than a decade old by then. The same technique is now used (with liquid crystal shutters) to evaluate interfaces in cars for drivers, maybe a variant would be useful for certain application areas of software (modulating the screen, perhaps)?
I recently fixed up an old bit of scientific apparatus, which was used to measure the cognitive workload of various aircraft cockpit designs. It used a method called visual occlusion, which you can guess the rest of—the pilots would sit in trainers with a set of glasses, that had spring-loaded solenoid flaps to block the pilots' vision selectively. The open time as well as the frequency of the system was experimentally varied until the pilot could fly the plane safely, for given conditions. The vacuum tube circuit that I repaired had a date stamp from the mid seventies but this technique was already more than a decade old by then. The same technique is now used (with liquid crystal shutters) to evaluate interfaces in cars for drivers, maybe a variant would be useful for certain application areas of software (modulating the screen, perhaps)?