Effects of Prior Information and Reward on Oculomotor and Perceptual Choices
Effects of Prior Information and Reward on Oculomotor and Perceptual Choices
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DOI：
10.1523/jneurosci.3120-08.2008
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发表时间：
2008-12-17
影响因子：
5.3
通讯作者：
Stone, Leland S.
中科院分区：
文献类型：
--
作者：
Liston, Dorion B.;Stone, Leland S.
对环境的期望影响运动行为。例如，在简单的任务中，关于哪个刺激事件可能会发生或哪个反应可能会得到奖励的先验知识会诱导采取有利行动的倾向（即，运动或反应偏差），特别是当感觉信息稀疏或模糊时。选择行为模型通过在早期的感觉输入阶段或在下游的运动输出阶段不平等地加权决策选项来解释这种偏差。这两种选择可以区分经验;前者预测与运动偏差相关的改变的感知，后者预测没有感知效果。通过改变目标或奖励位置的先验概率，我们在人类受试者的亮度选择任务中诱导了有偏见的眼动反应。我们发现，诱导的运动偏见与放大的感觉信号和内部噪音的亮度感知，没有一个系统的变化，感知的整体亮度。我们还发现，感官放大的幅度与亮度感知中的噪声量相关，与位于限制性内部感官噪声下游的乘法加权因子一致。我们的数据表明，先验知识（关于目标位置或奖励）平行地塑造感知和行动的视觉信号，但并没有提高质量（即，信噪比）。
Expectations about the environment influence motor behavior. In simple tasks, for example, prior knowledge about which stimulus event will likely occur or which response will likely be rewarded induces a tendency to take the favored action (i.e., a motor or response bias), especially when sensory information is sparse or ambiguous. Models of choice behavior account for this bias by weighting decision alternatives unequally, either at an early sensory-input stage or at a downstream motor-output stage. These two alternatives can be distinguished empirically; the former predicts an altered percept that correlates with motor bias, the latter predicts no perceptual effect. By varying the prior probability of target or reward location, we induced biased oculomotor responses in a brightness selection task with human subjects. We found that the induced motor bias was correlated with an amplification of both the sensory signals and internal noise underlying brightness perception, without a systematic change in perceived overall brightness. We also found that the magnitude of the sensory amplification was correlated with the amount of noise in the brightness percept, consistent with a multiplicative weighting factor located downstream from the limiting internal sensory noise. Our data demonstrate that prior knowledge (about target location or reward) shapes visual signals for perception and action in parallel but does not improve the quality (i.e., signal-to-noise ratio) of sensory processing.