Value-associated Stimuli Bias Ensemble Size Estimates
Value-associated Stimuli Bias Ensemble Size Estimates
复制标题
与值相关的刺激偏差整体大小估计
DOI：
10.1167/17.10.1298
复制
发表时间：
2017
影响因子：
1.8
通讯作者：
Dodgson D
中科院分区：
文献类型：
--
作者：
Dodgson D
在短暂接触多个对象数组之后，观察者似乎能够使用汇总统计来对对象属性进行概括性判断。这种整体感知被认为是通过提取“gist”克服严格的容量限制来帮助复杂场景的视觉认知。然而，即使一个场景充满了知觉的刺激，其中的一些刺激可能比其他刺激具有更大的动机显著性。我们实验室以前的工作表明，价值相关的刺激处理速度更快，并保持在WM比中性刺激，这表明这种刺激可能会偏见合奏知觉。为了调查，我们要求参与者调整响应圆，以匹配同时观看200 ms的12个不同大小的圆的平均大小（测试阵列）。在初始值学习阶段，所有圆圈都具有相同的颜色，并且根据数组颜色的不同，响应会获得高或低的奖励。在第二个测试阶段，测试阵列由三种不同颜色的圆圈组成，没有奖励。在不同的试验中，最小的四个或最大的四个圆圈以先前高或低的奖励相关颜色呈现。在第一个实验中，平均大小估计偏向于具有高奖励相关颜色的圆圈的平均大小，特别是当它们包括最大的圆圈时。这种价值偏向的影响，没有发现低奖励相关的颜色。为了研究这种效应是否发生在处理的后期，我们重复了实验，这次只在测试阶段试验中在测试阵列之后立即插入图案掩模。除了消除值偏置，测试阶段（但不是值学习阶段）的性能准确性显着优于第一个实验。我们的研究结果表明，以前奖励刺激偏见的提取汇总统计数据，我们认为，这种偏见的结果从缓慢的循环过程。
After brief exposure to multiple object arrays observers seem able to use summary statistics to make generalized judgments of object attributes. Such ensemble perception is thought to aid visual cognition of complex scenes by overcoming tight capacity limitations through extraction of'gist'. However, even when a scene is rich with perceptual consistencies, some stimuli within it may have greater motivational salience than others. Previous work from our lab has shown that value-associated stimuli are processed faster and maintained in WM better than neutral stimuli, suggesting that such stimuli may bias ensemble perception. To investigate we asked participants to adjust a response circle to match the average size of 12 heterogeneously sized circles viewed simultaneously for 200 ms (test array). In an initial value-learning phase, all circles had the same color and responses were rewarded with either a high or a low reward depending on array color. In a second test phase, test arrays comprised circles of three different colors and no rewards were forthcoming. On different trials, the smallest four or the largest four circles were presented in the previously high or low reward-associated color. In the first experiment, average size estimates were biased towards the mean size of circles with the high reward-associated color, especially when they comprised the largest circles. This value-biasing effect was not found for low reward-associated colors. To investigate whether this effect occurred late in processing, we repeated the experiment, this time inserting a pattern mask immediately after the test array in test phase trials only. In addition to value-biasing being eliminated, test phase (but not value learning phase) performance accuracy was significantly better than in the first experiment. Our results demonstrate that previously rewarding stimuli bias the extraction of summary statistics and we suggest that such biases result from slow recurrent processes.