Division of Neuroscience and Experimental Psychology, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom.
Vision Res. 2022 Oct;199:108073. doi: 10.1016/j.visres.2022.108073. Epub 2022 May 25.
Much of human activity involves perceptual or perceptuo-motor choice between options with uncertain outcomes. Previous research suggests that decisions in these contexts can be near-optimal in some circumstances but can also be significantly biased. Here we investigate how biases might depend on: i) discriminability of available choice outcomes, adjusted by manipulating the Expected Value (EV) function curvature; ii) outcome valence, which changes the tendency for risk seeking/aversive behaviour in cognitive decision making. In three experiments, participants set the size of a catcher in order to catch a dot moving on a random walk (with varying levels of predictability) after it emerged from behind an occluder. Catching and missing the dot were associated with scoring a variable number of outcome points depending on catcher size. In experiment 1 outcomes were most discriminable (high EV curvature) and catcher size settings were near-optimal. In experiments 2 and 3 outcomes were harder to discriminate (low EV curvature) and there was a significant bias to set the catcher size too small. Unlike cognitive decision making, the valence manipulation had little effect. Subsequent analyses suggest observed biases might reflect participants moving settings towards the region with highest EV curvature, where feedback is most informative. These data suggest that: i) unlike cognitive decisions, in this task choices are largely insensitive to outcome valence; ii) EV curvature is potentially an important factor when interpreting performance in such tasks; iii) Choice may be biased towards high EV curvature regions, consistent with value being placed on exploration to increase information return.
人类的许多活动都涉及到在不确定结果的选项之间进行感知或感知运动选择。以前的研究表明，在某些情况下，这些情况下的决策可以接近最优，但也可能存在明显的偏差。在这里，我们研究了偏差可能取决于：i）可用选择结果的可辨别性，通过操纵期望价值（EV）函数曲率进行调整；ii）结果效价，这会改变认知决策中风险寻求/厌恶行为的倾向。在三个实验中，参与者设置捕捉器的大小，以便在点从遮挡物后面出现后捕捉随机行走（具有不同程度的可预测性）中的点。捕捉和错过点与捕捉器大小相关，捕捉器大小决定了得分的变量数量。在实验 1 中，结果最可辨别（高 EV 曲率），捕捉器大小设置接近最优。在实验 2 和实验 3 中，结果更难辨别（低 EV 曲率），并且存在将捕捉器大小设置得太小的明显偏差。与认知决策不同，效价操纵几乎没有影响。后续分析表明，观察到的偏差可能反映了参与者将设置移向具有最高 EV 曲率的区域，在该区域反馈最具信息量。这些数据表明：i）与认知决策不同，在这项任务中，选择对结果效价的敏感度较低；ii）EV 曲率可能是解释此类任务中表现的重要因素；iii）选择可能偏向于高 EV 曲率区域，这与通过探索来增加信息回报的价值是一致的。
