不同模糊程度下的模糊决策的ERP研究

The Decision-making under Different Ambiguity Conditions: An Event-related Potential Study

选取"二择一的选择任务",以风险决策任务为基线,对不同概率区间所代表的三种不同模糊程度(0-100%、20-80%、40-60%)下的模糊决策进行了神经机制上的探究,结果发现:(1)三种不同模糊程度下的模糊决策在脑电上不存在差异;(2)与三种不同模糊程度相对应出现的三种相同风险程度的风险决策,在脑电上的激活有所不同;(3)三种模糊程度下的模糊决策与相对应出现的三种相同风险程度的风险决策,只有在40～60%和50～50%的条件下,脑电上是存在差异的。这些结果表明:被试在做决策时所依赖的参照点是相对的而不是绝对的;在40～60%和50～50%条件下,被试的决策过程有冲突的,是最困难的。

We applied the ERP technique to explore the neural mechanisms of ambiguity decision under different ambiguity degrees. We adopted the experiment paradigm of a variant of Ellsberg paradox. The ambiguity degrees included three ：0 - 100% ,20 -80% ,40 - 60%, representing by telling subjects the probability intervals to draw the red ball. For example, the probability intervals to draw the red ball between 0 and 100% was completely ambiguous. The probability intervals to draw the red ball was 50% in the risky decision. Sub- jects made the choice between the ambiguity decision and the risky decision. The results showed that： （ 1 ） there was no difference in the ERPs when processing the ambiguity decision of different degree ; （2） the ERPs of three risky decision were different; （3） the ERPs be- tween the ambiguity decision and the risky decision existed difference between the 40 - 60% and 50 - 50% conditions. These results showed that：the reference point subjects dependent in decision was not absolute but relative. When the difference between the two alter- natives was large, decision -making was easy, when the difference between the two alternatives was small, it will produce a decision - making conflicts, so the decision -making was difficulty.