It Really Is in Your Head: Thinking Hard and Long Can Cause Brain Drain - ScienceAlert

On the surface, that might sound like a contentious comparison, but a new study suggests thinking too hard and too long really can drain your brain, much like exercise can wear out the body.

The overabundance of glutamate is clearly a problem, and that's part of why it has been linked to brain drain.

In comparison, 16 other participants who were assigned easier tasks for the day didn't show signs of glutamate accumulation in this part of their brain.

Some researchers have proposed that a plummet in glucose triggers a loss of dopamine in the brain, which makes a person lose interest in certain cognitive tasks more easily.

"But our findings show that cognitive work results in a true functional alteration – accumulation of noxious substances – so fatigue would indeed be a signal that makes us stop working but for a different purpose: to preserve the integrity of brain functioning.".

"Taken together with previous fMRI data, these results support a neuro-metabolic model in which glutamate accumulation triggers a regulation mechanism that makes lPFC activation more costly, explaining why cognitive control is harder to mobilize after a strenuous workday," Pessiglione and colleagues conclude.