Feeling burned out, mentally exhausted, or brain-fried are all colloquial ways of talking about what neurologists formally refer to as "cognitive fatigue." It's a common feeling that nearly all of us suffer at some point, and can arise from such quotidian things as taking an all-day exam or just being overworked at a mentally taxing job.
Now, a new study suggests that there is actually something physically happening inside the brain that leads to cognitive fatigue. Indeed, the scientists behind a new paper in the journal Current Biology have shed some light on what is actually going on inside our heads. And it doesn't sound pleasant: "potentially toxic by-products" can build up in one's brain when one is cognitively fatigued.
