[adammarples]

But do they notice the difference between 4 hours and 5 hours? Or are they noticing something else entirely?

[jermberj]

To make the analogy proportional (according to the article), the difference would be something like "do they notice the difference between 1h 40m and 5 hours" (i.e. 3x more). My money would be on yes, they'd very much notice.