You need your sleep for your COGNITIVE
processing to perform at optimum levels.
The Big Bang Theory Season 2, Episode 6
I started doing some reading
on COGNITIVE vitality,
The Big Bang Theory Season 10, Episode 22
Impaired COGNITIVE function.
The Big Bang Theory Season 3, Episode 14
...which is required for COGNITIVE
reasoning, including scientific inquiry...
The Big Bang Theory Season 4, Episode 3
Well, it's not just doing
simple COGNITIVE tasks.
The Big Bang Theory Season 10, Episode 22