The Relative Influences of Priors and Sensory Evidence on an Oculomotor Decision Variable During Perceptual Learning
The Relative Influences of Priors and Sensory Evidence on an Oculomotor Decision Variable During Perceptual Learning
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DOI：
10.1152/jn.90629.2008
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发表时间：
2008-11-01
影响因子：
2.5
通讯作者：
Bennur, Sharath
中科院分区：
文献类型：
--
作者：
Gold, Joshua I.;Law, Chi-Tat;Bennur, Sharath
Gold JI，Law C-T，Connolly P，Bennur S。知觉学习期间先验和感觉证据对动眼神经决策变量的相对影响。 J Neurophysiol 100: 2653-2668, 2008。首次发表于 2008 年 8 月 27 日； doi：10.1152/jn.90629.2008。简单感觉运动任务的选择行为可以表现出试验与试验的依赖性。对于感知任务，这些依赖性反映了先前试验对选择的影响，这些选择也受到感官证据的指导，而感官证据通常在试验中是独立的。在这里，我们表明，先前的试验和感官证据对选择行为的相对影响可以通过训练来塑造，这样，当对相关感官证据的感知敏感性最弱时，先前的影响最强，然后随着敏感性的提高而稳定下降。我们训练猴子决定随机点运动的方向，并通过眼球运动来表明他们的决定。我们通过将当前选择与先前选择的加权平均值相关联来描述顺序依赖性。然后，我们将行为建模为漂移扩散过程，其中先前选择的加权平均值为决策变量提供了附加偏移，该决策变量整合了传入的运动证据来控制选择。随着综合运动证据的质量在数月的训练中不断提高，单个训练课程中的平均偏移量稳步下降。逐次试验的偏移幅度与与产生动眼神经反应的指令相关的信号相关，但与中颞区（代表运动刺激信息）或侧顶叶区（代表感觉运动转换）的神经活动无关。结果表明，培训可以根据先前的趋势和传入的感官证据来塑造期望的相对贡献，以选择和准备视觉引导的行动。
Gold JI, Law C-T, Connolly P, Bennur S. The relative influences of priors and sensory evidence on an oculomotor decision variable during perceptual learning. J Neurophysiol 100: 2653-2668, 2008. First published August 27, 2008; doi:10.1152/jn.90629.2008. Choice behavior on simple sensory-motor tasks can exhibit trial-to-trial dependencies. For perceptual tasks, these dependencies reflect the influence of prior trials on choices that are also guided by sensory evidence, which is often independent across trials. Here we show that the relative influences of prior trials and sensory evidence on choice behavior can be shaped by training, such that prior influences are strongest when perceptual sensitivity to the relevant sensory evidence is weakest and then decline steadily as sensitivity improves. We trained monkeys to decide the direction of random-dot motion and indicate their decision with an eye movement. We characterized sequential dependencies by relating current choices to weighted averages of prior choices. We then modeled behavior as a drift-diffusion process, in which the weighted average of prior choices provided an additive offset to a decision variable that integrated incoming motion evidence to govern choice. The average magnitude of offset within individual training sessions declined steadily as the quality of the integrated motion evidence increased over many months of training. The trial-by-trial magnitude of offset was correlated with signals related to developing commands that generate the oculomotor response but not with neural activity in either the middle temporal area, which represents information about the motion stimulus, or the lateral intraparietal area, which represents the sensory-motor conversion. The results suggest that training can shape the relative contributions of expectations based on prior trends and incoming sensory evidence to select and prepare visually guided actions.