What makes a decision difficult? Two key factors are conflict and surprise: conflict emerges with multiple competing responses and surprise occurs with unexpected events. Conflict and surprise, however, are often thought of as parsimonious accounts of decision making rather than an integrated narrative. We sought to determine whether conflict and/or surprise concurrently or independently elicit effortful decision making. Participants made a series of diagnostic decisions from physiological readings while electroencephalographic (EEG) data were recorded. To induce conflict and surprise, we manipulated task difficulty by varying the distance between a presented physiological reading and the category border that separated the two diagnoses. Whereas frontal theta oscillations reflected surprise – when presented readings were far from the expected mean, parietal alpha and beta oscillations indicated conflict – when readings were near the category border. Our findings provide neural evidence that both conflict and surprise engage cognitive control to employ effort in decision making.

是什么使决策变得困难？两个关键因素是冲突和突发事件：冲突是由多个相互竞争的响应产生的，突发事件是由突发事件引起的。然而，冲突和惊奇常常被认为是对决策的简约描述，而不是综合的叙述。我们试图确定冲突和/或意外是同时还是独立引发了艰难的决策。在记录脑电图（EEG）数据的同时，参与者根据生理学读数做出了一系列诊断决策。为了引起冲突和意外，我们通过改变呈现的生理读数与分隔两个诊断的类别边界之间的距离来操纵任务难度。额叶theta振荡反映出令人惊讶-当所呈现的读数与预期均值相差甚远时，当读数接近类别边界时，顶α和β振荡表明存在冲突。我们的发现提供了神经证据，表明冲突和惊奇都参与了认知控制，从而在决策过程中付出了努力。