阅读文献:
Körding, K. P., & Wolpert, D. M. (2006). Bayesian decision theory in sensorimotor control. trends in cognitive sciences, 10(7), 319-326.
文献链接:
Bayesian decision theory in sensorimotor control - ScienceDirect
Abstract
1) Nervous system needs to estimate variability and noise when processing signials.
2) Human behaviour is close to that predicted by Bayesian Decision Theory, which defines optimal behaviour in a world characterized by uncertainty, and provides a coherent way of describing sensorimotor processes.
Introduction
1) Determining movement is a decision process in the central nervous system always companying with uncertainty.
→ Bayesian statistics provides a systematic way of solving problems in the presence of uncertainty.
2) Decision theory: The cost of each movement (such as energy consumed) must be weighed against the potential rewards that can be obtained by moving.
→ Rational choice of the movement is that maximizes utility according to decision theory.
Estimation using Bayes rule
Bayesian integration in motor control
1) With increasing noise in the sensory feedback subjects should increase the weight of the prior and decrease the weight of their sensory feedback in their final estimate of the location.
(详见Day36阅读文献)
在Day36文献中,上图b的纵轴为slope,而本文献中同样的图纵轴为weight of prior
猜测原因:在上图a中,deviation from target即为posterior的估计值,根据贝叶斯模型posterior最优估计的均值为:E(posterior)=αE(prior)+(1-α)E(likelihood),因此上图a和b中的slope即prior的weight,值为
2) From Fig. 1(e), subjects in this task exhibit a strategy very similar to the one predicted by optimal Bayesian statistics (the red curve).
Bayesian integration in perception
human perception is close to the Bayesian optimal suggesting the Bayesian process may be a fundamental element of sensory processing.
Bayesian cue combination
1) Bayesian processes can also be used to understand how cues from two different modalities can be combined into a single estimate.
2) Calculating this optimally in a Bayesian way means that the weighing will depend on the relative uncertainties in the cues.