DECISION PROCESSES IN DETECTION AND DISCRIMINATION

描述（由申请人提供）：本研究计划的目标是通过表征在不同时间配置下使用相同基本刺激的三项任务的决策过程差异来更好地了解人类听觉的基本方面：强度辨别，增量检测和前向掩蔽。经典的和普遍存在的能量检测器模型的决策过程提供了一个很好的帐户的数据强度歧视。然而，需要能量检测的替代方案来考虑在增量检测和前向掩蔽中获得的结果，以及大多数其他检测和辨别任务。决策过程的替代模型，特别是“模板匹配”，目前定义不清，预测模糊。我们将通过确定整体刺激水平变化的影响和引入背景噪声的影响来表征这些任务中决策过程的特性。性能指标包括自适应阈值，心理测量功能，内部噪声的直接测量，以及刺激的具体特征与每个受试者对个别试验的反应的相关性。具体目标是：1）确定外周非线性和心理测量函数斜率之间的关系; 2）比较强度辨别和增量检测中的决策过程; 3）确定噪声对强度辨别、增量检测和前掩蔽的影响; 4）开发和比较内部噪声的直接测量。这项研究工作将导致更好地表征替代决策过程，与这里考虑的三个基本心理物理任务中的每一个相关联的决策过程的具体功能的详细测试，适合于每个任务的内部噪声的措施，以及更好地理解多阶段掩蔽模型中的外周压缩和内部噪声的相互作用。

DESCRIPTION (provided by applicant): The goal of this research program is to develop a better understanding of fundamental aspects of human hearing by characterizing differences in decision processes for three tasks that use the same basic stimuli in different temporal configurations: intensity discrimination, increment detection, and forward masking. The classic and ubiquitous energy detector model of the decision process provides a good account of data for intensity discrimination. An alternative to energy detection, however, is required to account for results obtained in increment detection and forward masking, as well as the majority of other detection and discrimination tasks. Alternative models of the decision process, in particular "template matching", are currently poorly defined and make vague predictions. We will characterize properties of the decision process in these tasks by determining the effects of variability in overall stimulus level and the effects of introducing background noise. Performance measures include adaptive thresholds, psychometric functions, direct measures of internal noise, and the correlation of specific features of stimuli with each subject's response on individual trials. The specific aims are: 1) to determine the relation between peripheral nonlinearity and the slopes of psychometric functions; 2) to compare decision processes in intensity discrimination and increment detection; 3) to determine the effects of noise on intensity discrimination, increment detection and forward masking; and 4) to develop and compare direct measures of internal noise. This research effort will result in a better characterization of alternative decision processes, a detailed test of specific features of the decision process associated with each of the three basic psychophysical tasks considered here, measures of internal noise appropriate to each task, and a better understanding of the interaction of peripheral compression and internal noise in multi-stage models of masking.