Human brain representation of free using fMRI and ECoG

本研究旨在利用神经成像技术研究免费物品对人类偏好的影响。除了FREE的脑图外，我们还希望通过记录难治性癫痫患者的皮层脑电来了解人脑中FREE处理的时间进程。例如，有报道称，高档昂贵的巧克力和廉价的巧克力都是以合适的价格同时赠送的，人们更喜欢前者，因为它会给他们带来更多的乐趣。然而，如果便宜的巧克力定价为零，人们更喜欢选择零价巧克力。通过使用这一实验范式(Shampanier，2007)，我们在行为上证实了这种偏好倒置，我们的fMRI研究揭示了内侧前额叶区域对零价商品的额外激活。

The present study aims to investigate the effect of free things for human preference by using neuroimaging technique. In addition to the brain map of free, we would like to find out the time course of free processing in human brain using the electrocorticogram recorded in intractable epilepsy patients. For example, it has been reported that the high-grade expensive chocolates and cheep chocolates are simultaneously presented with proper prices, people prefer the former one because it will give them more pleasure. However, if the cheap ones are priced as zero, people prefer to select zero-priced chocolates. By using this experimental paradigm (Shampanier, 2007), we confirmed this inversion of preference behaviorally and our fMRI study revealed the extra-activation of medial prefrontal area for zero-priced things.