Benozzo Danilo, Ferrucci Lorenzo, Genovesio Aldo
Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy.
Cereb Cortex. 2023 Mar 10;33(6):2958-2968. doi: 10.1093/cercor/bhac253.
Our representation of magnitudes such as time, distance, and size is not always veridical because it is affected by multiple biases. From a Bayesian perspective, estimation errors are considered to be the result of an optimization mechanism for the behavior in a noisy environment by integrating previous experience with the incoming sensory information. One influence of the distribution of past stimuli on perceptual decisions is represented by the regression toward the mean, a type of contraction bias. Using a spatial discrimination task with 2 stimuli presented sequentially at different distances from the center, we show that this bias is also present in macaques when comparing the magnitude of 2 distances. We found that the contraction of the first stimulus magnitude toward the center of the distribution accounted for some of the changes in performance, even more so than the effect of difficulty related to the ratio between stimulus magnitudes. At the neural level in the dorsolateral prefrontal cortex, the coding of the decision after the presentation of the second stimulus reflected the effect of the contraction bias on the discriminability of the stimuli at the behavioral level.
我们对时间、距离和大小等量值的表征并非总是准确无误的，因为它会受到多种偏差的影响。从贝叶斯的角度来看，估计误差被认为是一种优化机制的结果，该机制通过将先前的经验与传入的感官信息相结合，来应对嘈杂环境中的行为。过去刺激分布对感知决策的一种影响表现为向均值回归，这是一种收缩偏差。通过使用一种空间辨别任务，在不同距离中心处依次呈现两个刺激，我们发现，在比较两个距离的大小时，猕猴中也存在这种偏差。我们发现，第一个刺激量值向分布中心的收缩解释了部分性能变化，甚至比与刺激量值比率相关的难度效应更甚。在背外侧前额叶皮层的神经层面，第二个刺激呈现后的决策编码反映了收缩偏差对行为层面刺激可辨别性的影响。
