On theanine, brain waves may shift like attention, not like sedation
In one small lab study, theanine lowered the brain's background alpha rhythm while raising the part of it that builds as attention is aimed. This is electrical activity, not how focused anyone felt.
What the study found
One brain rhythm fell overall and rose where attention was aimed
One rhythm moving two ways at once is what separates a targeted effect from simple sedation. L-theanine lowered background alpha activity, a brain-wave rhythm, while raising the part of it that builds in anticipation during an attention task.
The caveat · Brain waves only, not behaviour
This is electrical activity recorded in one small single-lab study, not behaviour and not how focused anyone felt or performed. A distinct signature is not the same thing as better concentration.
What we don't know
This is electrical activity recorded in one small single-lab study, not behaviour and not how focused anyone felt or performed. A distinct signature is not the same thing as better concentration.