Myczek Kristoffer, Simons Daniel J
University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, USA.
Percept Psychophys. 2008 Jul;70(5):772-88. doi: 10.3758/pp.70.5.772.
People can perceive the individual features of an object by focusing attention on it and binding the features together at a location. Some perceptual processing can occur without focusing attention on each object, though; people may even be able to extract summary information about the sizes of all the objects in a display, essentially computing the mean size at a glance. Evidence that people can judge the mean size of an array efficiently and accurately has been used to support the strong claim that people use a global, parallel process to extract a statistical summary of the average size of the objects in the display. Such claims are based both on the accuracy of performance and on the supposition that performance exceeds what would be possible with serial, focused attention. However, these studies typically have not examined the limits of performance with focused-attention strategies. Through experiments and simulations, we show that existing evidence for mean size perception can be explained through various focused-attention strategies, without appealing to a new mechanism of average size perception. Although our evidence does not eliminate the possibility that people do perceive the average size of all the objects in a display, it suggests that simpler mechanisms can accommodate the existing data.
人们可以通过将注意力集中在一个物体上并在某个位置将其特征绑定在一起，从而感知该物体的各个特征。不过，有些感知处理过程在不将注意力集中在每个物体上时也会发生；人们甚至可能能够提取有关显示屏中所有物体大小的概要信息，基本上一眼就能算出平均大小。人们能够高效且准确地判断一组物体的平均大小，这一证据被用来支持这样一种有力的观点，即人们使用一种全局的、并行的过程来提取显示屏中物体平均大小的统计概要。此类观点既基于表现的准确性，也基于这样一种假设，即这种表现超过了通过串行的、集中注意力的方式所能达到的程度。然而，这些研究通常并未考察集中注意力策略下的表现极限。通过实验和模拟，我们表明，现有的关于平均大小感知的证据可以通过各种集中注意力策略来解释，而无需诉诸一种新的平均大小感知机制。虽然我们的证据并未排除人们确实能感知显示屏中所有物体平均大小的可能性，但它表明更简单的机制就能解释现有数据。
