The 12 volunteers, all aged in their 20s, wore heart monitors and had electrodes attached to their heads as each placed a piece of dark chocolate on the tongue and, without chewing, indicated when it started to melt.

• 年龄均为20多岁的12名志愿者身上连着心脏监测仪，头上连着电极，然后每个人把一块黑巧克力放在舌头上，不嚼，以便观察它何时开始融化。