DECISION PROCESSES IN DETECTION AND DISCRIMINATION

描述（由申请人提供）：本研究项目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种任务的决策过程的差异，从而更好地理解人类听力的基本方面：强度辨别、增量检测和前向掩蔽。决策过程中经典且普遍存在的能量检测器模型为强度判别提供了很好的数据说明。然而，需要一种替代能量检测的方法来考虑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识别任务。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。我们将通过确定总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。表现测量包括自适应阈值、心理测量功能、内部噪声的直接测量，以及刺激的特定特征与每个受试者在个别试验中的反应的相关性。具体目的是：1)确定外围非线性与心理测量函数斜率之间的关系；2)比较强度判别和增量检测的决策过程；3)确定噪声对强度识别、增量检测和前向掩蔽的影响；4)制定和比较内部噪声的直接测量方法。这项研究将有助于更好地描述可选决策过程，详细测试与本文所考虑的三个基本心理物理任务相关的决策过程的具体特征，测量适合于每个任务的内部噪声，以及更好地理解多阶段掩蔽模型中外围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.