How can self-control experiments serve to measure impulsivity at the time of choice?

In theory, any healthy person without any type of psychiatric and neurological anomaly responds to the environment. That means being reactive/active/passive. But these characteristics are not so easy to measure. There is also not much agreement about the meaning of these terms.

Commitment, choice and self-control

Improving cognitive control: Is theta neurofeedback training associated with proactive rather than reactive control enhancement?

Computational and neuroscientific models

Predictive coding and neural mechanisms underlying the perception.

EEG NIRS TMS fMRI, VideoSync and behavioral data. 

Machine learning, signal and image processing, Big Data, etc...

Affective Computing