This question already has an answer here:
A previous question dealt with whether it is possible to catch up on lost sleep. This question is a little different.
Assume that a healthy adult has been deprived of sleep for "x" hours. How much sleep is required to restore healthy brain function, compared to sleep lost?
I wouldn't think the hours needed could be predicted by a linear scale.
Is there some predictable relationship between the two and what type of relationship is it?