What really goes on when two people communicate? Greg Stephens of Princeton University and colleagues have used functional MRI to monitor the brain activity of both a speaker and a listener.
They find that when real communication takes place, the listener's brain is, on average, spatially and temporally correlated with that of the speaker, the one mirroring the other with a delay. They also find an anticipatory component in the listener's brain that predicts what will be coming next in the speaker. This effect appears to be stronger the greater the degree of understanding of the listener.
Fans of Star Trek will be amused to find that perhaps humans do have their own version of the "Vulcan mind meld" but via speech alone.