Uncertainty of visual measurement and efficient allocation of sensory resources

Neural and perceptual signatures of efficient sensory coding

The mammalian brain is a metabolically expensive device, and evolutionary pressures have presumably driven it to make productive use of its resources. For sensory areas, this concept has been expressed more formally as an optimality principle: the brain maximizes the information that is encoded about relevant sensory variables, given available resources. Here, we develop this efficiency principle for encoding a sensory variable with a heterogeneous population of noisy neurons, each responding to a particular range of values. The accuracy with which the population represents any particular valu…

内隐与外显视觉注意的主动推理模型

An Active Inference Model of Covert and Overt Visual Attention

该研究基于主动推理框架提出内隐与外显视觉注意模型，通过动态优化感官精度最小化自由能，经Posner线索化等任务验证，模型可复现返回抑制等注意现象，揭示了不同注意模式的反应时与适应性差异。

On the role of time in perceptual decision making

According to the dominant view, time in perceptual decision making is used for integrating new sensory evidence. Based on a probabilistic framework, we investigated the alternative hypothesis that time is used for gradually refining an internal estimate of uncertainty, that is to obtain an increasingly accurate approximation of the posterior distribution through collecting samples from it. In the context of a simple orientation estimation task, we analytically derived predictions of how humans should behave under the two hypotheses, and identified the across-trial correlation between error and…

Optimal measurement of visual motion across spatial and temporal scales

Sensory systems use limited resources to mediate the perception of a great variety of objects and events. Here a normative framework is presented for exploring how the problem of efficient allocation of resources can be solved in visual perception. Starting with a basic property of every measurement, captured by Gabor's uncertainty relation about the location and frequency content of signals, prescriptions are developed for optimal allocation of sensors for reliable perception of visual motion. This study reveals that a large-scale characteristic of human vision (the spatiotemporal contrast se…