Krishnamurthy Kamesh, Nassar Matthew R, Sarode Shilpa, Gold Joshua I
Department of Neuroscience, University of Pennsylvania 19104-6074.
Department of Cognitive, Linguistic, and Psychological Sciences, Brown University 02912.
Nat Hum Behav. 2017;1. doi: 10.1038/s41562-017-0107. Epub 2017 May 8.
Prior expectations can be used to improve perceptual judgments about ambiguous stimuli. However, little is known about if and how these improvements are maintained in dynamic environments in which the quality of appropriate priors changes from one stimulus to the next. Using a sound-localization task, we show that changes in stimulus predictability lead to arousal-mediated adjustments in the magnitude of prior-driven biases that optimize perceptual judgments about each stimulus. These adjustments depend on task-dependent changes in the relevance and reliability of prior expectations, which subjects update using both normative and idiosyncratic principles. The resulting variations in biases across task conditions and individuals are reflected in modulations of pupil diameter, such that larger stimulus-evoked pupil responses correspond to smaller biases. These results suggest a critical role for the arousal system in adjusting the strength of perceptual biases with respect to inferred environmental dynamics to optimize perceptual judgements.
先前的预期可用于改善对模糊刺激的感知判断。然而，对于在动态环境中这些改善是否以及如何得以维持，我们却知之甚少，在动态环境中，合适先验的质量会因刺激的不同而发生变化。通过一项声音定位任务，我们发现刺激可预测性的变化会导致由唤醒介导的先验驱动偏差大小的调整，从而优化对每个刺激的感知判断。这些调整取决于先验预期的相关性和可靠性中与任务相关的变化，而受试者会使用规范和特质原则对这些预期进行更新。在不同任务条件和个体之间，偏差的这种变化会反映在瞳孔直径的调节上，即更大的刺激诱发瞳孔反应对应更小的偏差。这些结果表明，唤醒系统在根据推断的环境动态调整感知偏差强度以优化感知判断方面起着关键作用。
