There's a different type of brain-to-brain interface: I remember reading something about neurofeedback(eeg biofeedback) , when they trained to users to increase

There's a different type of brain-to-brain interface: I remember reading something about neurofeedback(eeg biofeedback) , when they trained to users to increase a certain brainwave pattern(their alpha wave) in some synchronized fashion and that created a strong feeling of contentedness between them . I'm not sure this is true though, because the field of neurofeedback has plenty of bullshit.