It takes two seconds to decide upon which special-function key to press. Deciding among abstract symbols is a high-level cognitive function. Not only is this decision not boring, the user actually experiences amnesia! Real amnesia! The time-slice spent making the decision simply ceases to exist.

Hmm. Not to be "that vim guy", but when those navigation/search/etc become muscle memory, it's not really a high level function anymore to do things like searching.. at least in terms path decideability. The sort of amnesia they talk about here happens to me whenever I need to pull my hands away from the keyboard. Though, their study probably didn't have that many opinionated text editor nerds.