Neurocortical monitor

A neurocortical monitor, sometimes called a cortical monitor, was a small sensor used to record brain activity.

In 2368, Reginald Barclay used pieces of a discarded neurocortical monitor to construct a device which would block telepathy. (SS TNG (Thinking of You))

In 2374, Commander Bruce Maddox wore cortical monitors while recovering from injuries caused in the attack on the Daystrom Institute Annex on Galor IV. 

Later that year, $𝜇$ wore a neurocortical monitor while being treated in the USS Sovereign (prototype)'s sickbay. 

In 2375, Crell Moset used neurocortical monitors on Dal Corbin and a Jem'Hadar while experimenting on them. 

In 2378, the Doctor used cortical monitors on Sek and Tuvok when the former administered the fal-tor-voh treatment to the latter. 

Later that year, Jarem Kaz used cortical monitors on Chakotay during his physical. 

Towards the end of the year, the USS Enterprise (NCC-1701-E)'s EMH used cortical monitors on Jipta. 

In 2380, T'Ryssa Chen wore a cortical monitor while in telepathic communication with NGC 6281.