Dai, Department of Speech, Language, and Hearing Sciences,University of Arizona, Tucson, AZ 85721, USA.
Psychol Rev. 2012 Oct;119(4):770-88. doi: 10.1037/a0029343. Epub 2012 Jul 30.
A fundamental issue in the design and the interpretation of experimental studies of perception relates to the question of whether the participants in these experiments could perform the perceptual task assigned to them using another feature, or cue, than that intended by the experimenter. An approach frequently used by auditory- and visual-perception researchers to guard against this possibility involves applying random variations to the stimuli across presentations or trials so as to make the "unwanted" cue unreliable for the participants. However, the theoretical basis of this widespread practice is not well developed. In this article, we describe a 2-channel model based on general principles of psychophysical signal detection theory, which can be used to assess the respective contributions of the unwanted cue and of the primary cue to performance or thresholds measured in perceptual discrimination experiments involving stimulus randomization. Example applications of the model to the analysis of results obtained in representative studies from the auditory- and visual-perception literature are provided. In several cases, the results of the model-based analyses indicate that the effectiveness of the randomization procedure was less than originally assumed by the authors of these studies. These findings underscore the importance of quantifying the potential influence of unwanted cues on the results of psychophysical experiments, even when stimulus randomization is used.
在设计和解释感知实验研究时，一个基本问题涉及到这样一个问题，即这些实验的参与者是否可以使用实验者意图之外的另一种特征或线索来执行分配给他们的感知任务。听觉和视觉感知研究人员经常采用的一种方法是，在呈现或试验过程中对刺激施加随机变化，以使“不需要的”线索对参与者不可靠。然而，这种广泛实践的理论基础还没有得到很好的发展。在本文中，我们描述了一个基于心理物理信号检测理论一般原理的双通道模型，该模型可用于评估在涉及刺激随机化的感知辨别实验中，不需要的线索和主要线索对性能或阈值的各自贡献。该模型的应用实例分析了来自听觉和视觉感知文献中具有代表性的研究结果。在几种情况下，基于模型的分析结果表明，随机化程序的有效性低于这些研究的作者最初假设的有效性。这些发现强调了即使使用刺激随机化，也需要量化不需要的线索对心理物理实验结果的潜在影响。
