They had people play this game while they were being scanned in an fMRI, and two conditions: in some trials, they're told, "You're playing another person who's playing right now. We'll match up your behavior at the end and pay you if you win."
Tenían gente jugando este juego mientras que se está escaneando en un fMRI y dos condiciones: en algunos ensayos, les dicen que está jugando otra persona que está jugando ahora mismo y vamos a probar su comportamiento al final y le pagaremos si gana.