Cognitive Neuroimaging Unit, NeuroSpin Center, CEA, INSERM, Université Paris-Saclay, F-91191 Gif/Yvette, France; Mathematical Thinking Lab, School of Education and School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
Cognitive Neuroimaging Unit, NeuroSpin Center, CEA, INSERM, Université Paris-Saclay, F-91191 Gif/Yvette, France; Collège de France, Université Paris-Sciences-Lettres (PSL), 11 Place Marcelin Berthelot, 75005 Paris, France.
Cognition. 2022 Jul;224:105069. doi: 10.1016/j.cognition.2022.105069. Epub 2022 Feb 24.
Several theories of decision making assume that optimal decisions are reached by computing a prior distribution over possible responses, and then updating it according to the evidence received. We show how this prior replacement, with its two processing stages, can be captured with a simple behavioral method: tracking the finger movement as participants point to a response location. On each trial, participants saw a number and pointed to its location on a number line. In two experiments, we manipulated either the prior, via the distribution of target numbers, or the initial finger direction, via explicit instruction. In both experiments, when a trial started the participants pointed towards the instructed direction, and in the last part of the trial they pointed towards the target. Critically, between these two stages there was a third, interim stage in which the participants pointed towards the prior before deviating towards the target. Transient pointing towards the prior was observed even when it induced a brief deviation away from the target. This pattern fits a model wherein decisions are first driven by prior knowledge, followed by the accumulation of trial-specific evidence. We propose that the number-to-position mapping task with finger tracking is a powerful paradigm to investigate fine-grained aspects of priors in a simple decision-making scenario.
几种决策理论假设，通过计算可能的反应的先验分布，然后根据接收到的证据对其进行更新，可以做出最优决策。我们展示了如何用一种简单的行为方法来捕捉这种先验替换，它有两个处理阶段：跟踪参与者指向响应位置的手指运动。在每次试验中，参与者都会看到一个数字，并在数字线上指向其位置。在两项实验中，我们通过目标数字的分布来操纵先验，或者通过明确的指令来操纵初始手指方向。在这两项实验中，当试验开始时，参与者会指向指示的方向，在试验的最后部分，他们会指向目标。关键是，在这两个阶段之间，有一个第三阶段，即中间阶段，在此阶段，参与者会在偏离目标之前指向先验。即使先验会导致短暂的偏离目标，也会观察到短暂的指向先验。这种模式符合这样一种模型，即决策首先由先验知识驱动，然后再根据特定于试验的证据进行积累。我们提出，用手指跟踪进行数字到位置的映射任务是一个强大的范例，可以在简单的决策场景中研究先验的细粒度方面。
