查看文章

Physical conflicts tend to escalate. For example, as tit-for-tat exchanges between two children escalate, both will often assert that the other hit him or her harder. Here we show that, in such situations, both sides are reporting their true percept and that the escalation is a natural by-product of neural processing. Six pairs of naıve participants took part in a tit-for-tat experiment. Each member of a pair rested his or her left index finger in a molded support. A force transducer, which was attached to a lightweight lever of a torque motor, was placed on top of this finger (Fig. 1, inset). A trial was started by one torque motor producing a 0.25 N force on one participant’s finger. Participants then took turns to press with their right index finger down for 3 s on the force transducer resting on the other’s left index finger. They were instructed to apply the same force on the other participant that had just been exerted on them. Each …