Bayesian and "Anti-Bayesian" Biases in Sensory Integration for Action and Perception in the Size-Weight Illusion
Bayesian and "Anti-Bayesian" Biases in Sensory Integration for Action and Perception in the Size-Weight Illusion
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DOI：
10.1152/jn.00814.2009
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发表时间：
2010-03-01
影响因子：
2.5
通讯作者：
Smith, Maurice A.
中科院分区：
文献类型：
--
作者：
Brayanov, Jordan B.;Smith, Maurice A.
Brayanov JB, Smith MA。贝叶斯和“反贝叶斯”偏差在大小-重量错觉中行动和知觉的感觉整合中。中国生物医学工程学报（英文版），2009,31(4):557 - 557。首次发表于2010年1月20日；doi: 10.1152 / jn.00814.2009。一磅铅和一磅羽毛哪个更重？这个经典的恶作剧问题掩盖了一个简单但令人惊讶的事实：当被举起来时，铅的重量感觉更重——这种现象被称为尺寸-重量错觉。为了估计物体的重量，我们的中枢神经系统结合了两种不完美的信息来源：基于物体外观的先验预期，以及举起物体时的直接感觉信息。贝叶斯定理（或贝叶斯定律）定义了将多个信息源组合在一起以获得最大准确估计的统计最优方法。在这里，我们询问结合这些信息源的机制是否为感知和行动产生统计上最优的权重估计。我们首先研究了受试者在另一只手拿开物体时保持一只手稳定的能力，在这种情况下，关于物体重量的感官信息有时与先前基于物体大小的预期相冲突。由于稳定支撑手的能力取决于产生的电机指令，该指令考虑了提升时间和物体重量，因此手部运动可用于测量电机系统对重量估计的偏差。我们发现，这些运动系统的重量估计反映了先验预期与实时本体感觉信息的整合，以贝叶斯统计最优的方式贴现了意外的感觉信息。这就产生了一种运动尺寸-重量的错觉，这种错觉总是使重量估计偏向于先前的预期。相反，当受试者比较两个物体的重量时，他们的感知违背了贝叶斯定律，夸大了意想不到的感官信息的价值。这就产生了一种感知大小权重的错觉，这种错觉会使感知偏离先前的预期。我们称这种效应为“反贝叶斯”，因为偏差与贝叶斯积分相反。我们的研究结果表明，在体重估计的神经系统中，两种根本不同的整合先验预期和感觉信息的策略共存。
Brayanov JB, Smith MA. Bayesian and "anti-Bayesian" biases in sensory integration for action and perception in the size-weight illusion. J Neurophysiol 103: 1518-1531, 2010. First published January 20, 2010; doi: 10.1152/jn.00814.2009. Which is heavier: a pound of lead or a pound of feathers? This classic trick question belies a simple but surprising truth: when lifted, the pound of lead feels heavier-a phenomenon known as the size-weight illusion. To estimate the weight of an object, our CNS combines two imperfect sources of information: a prior expectation, based on the object's appearance, and direct sensory information from lifting it. Bayes' theorem (or Bayes' law) defines the statistically optimal way to combine multiple information sources for maximally accurate estimation. Here we asked whether the mechanisms for combining these information sources produce statistically optimal weight estimates for both perceptions and actions. We first studied the ability of subjects to hold one hand steady when the other removed an object from it, under conditions in which sensory information about the object's weight sometimes conflicted with prior expectations based on its size. Since the ability to steady the supporting hand depends on the generation of a motor command that accounts for lift timing and object weight, hand motion can be used to gauge biases in weight estimation by the motor system. We found that these motor system weight estimates reflected the integration of prior expectations with real-time proprioceptive information in a Bayesian, statistically optimal fashion that discounted unexpected sensory information. This produces a motor size-weight illusion that consistently biases weight estimates toward prior expectations. In contrast, when subjects compared the weights of two objects, their perceptions defied Bayes' law, exaggerating the value of unexpected sensory information. This produces a perceptual size-weight illusion that biases weight perceptions away from prior expectations. We term this effect "anti-Bayesian" because the bias is opposite that seen in Bayesian integration. Our findings suggest that two fundamentally different strategies for the integration of prior expectations with sensory information coexist in the nervous system for weight estimation.