Caffeine study 3

Caffeine improved subjective alertness at 60 min and accuracy on the attention-switching task at 90 min.

The L-theanine and caffeine combination improved both speed and accuracy of performance of the attention-switching task at 60 min, and reduced susceptibility to distracting information in the memory task at both 60 min and 90 min.

These results replicate previous evidence which suggests that L-theanine and caffeine in combination are beneficial for improving performance on cognitively demanding tasks.

Study: 
https://pubmed.ncbi.nlm.nih.gov/18681988/