... what is it?

See thread for general idea: EEG Brainwaves and Personality Type: What would they look like+Neurofeedback changes?

I'm going to assume you briefed over it and you know what EEGs are and what neurofeedback is. If you don't now is a good time to find out. Don't worry. I'll wait.

oooookkk... So what do you think the brainwaves of an NT would look like? Here's what I figure:

Resting: Mid Alpha (chronic daydreaming)
Stimulated: High Alpha/Low Beta (Half big picture half detailed cognition)

Mid Synchrony

Resting: Low Beta (Introvert but still near the daydreamy state)
Stimulated: High beta

Medium/Low Synchrony (Beta waves are more random than the other states, resulting in lower synchrony)

Resting: Mid Alpha (Extravert)
Stimulated: Mid Beta (Logical)

Low Synchrony

Resting: Mid Beta
Stimulated: High Beta

Low Synchrony

And of course it's complete conjecture. Justification:
-Beta is associated with cognition, albeit left-brain cognition. I figured the NTJs would have more of this with their Dom/Sec Te.
-Alpha is the "relaxed, open" frequency. Meditators produce a lot of this. Given that extraverts are supposed to default to this state, even the "introverted" extraverts like ENTPs, I set them up with alpha frequencies.
-If it's High/Low, it means it's borderline. Beta is higher than Alpha is higher than Theta is higher than Delta, but if it's borderline it means that they share traits of one another. Since we're all intuitives here, there shouldn't be anyone with dominant Theta waves in resting state.
-Synchronization refers to the synchronization between the left and right hemispheres. I think the Tes would have less of this, being left-brain dominated. INTPs and ENTPs have a tendency to be off the wall and random: This suggests that they are integrating more information from disparate parts of the brain, which would entail greater synchrony. Really super duper high synchrony would probably start to make you an NF, not an NT, because you'd be too mushy with all that emotional data being integrated into your decisions.

I can try to explain the gaps of info if you think there are any. Bit tired.

Anyway, I know I'm right. Practiced meditators could probably comment here noticing a change in attitude after a while. Guess what's practiced: Intense relaxation and greater sense of self. Guess what gives both: Alpha waves and high brain synchronization.

K. Almighty

PS if you're really interested in the idea of neurofeedback, like me, look up this stuff:

OpenFocus, training on how to produce relaxing alpha waves w/out equipment
OpenEEG, how to build a "cheap" eeg from scratch
Emotiv EPOC and Neurosky, some EEGs that don't come with the risk of electrocuting yourself and the added bonus of being video game controllers (yes, jedi powers)