PSYCHOPHYSICAL STUDY OF VIBROTACTILE TEMPORAL SUMMATION

该项目广泛的长期目标是通过对振动触觉时间总和的实验研究来扩展我们对感觉系统的时间属性的知识。通过测量心理物理阈值来检测呈现在手部无毛皮肤上的正弦刺激，时间整合的基本机制应该会揭示出来。其目的是在实验上分离出两种可能的基本机制，可能是总和和神经整合，负责所有感觉系统中的时间总和，并定义它们在振荡式作用下工作的条件。通过测量当外部背景噪声的水平和频谱特征被操纵时用于检测单脉冲和多脉冲刺激的心理物理阈值，将可能检验这样的假设，即感觉系统中的总和可能需要足够水平的内部或外部噪声，从而在系统的神经反应中引入大量的可变性，以重复呈现相同的刺激。通过测量用于检测被噪声分隔的多个脉冲的阈值，该阈值旨在扰乱刺激终止后可能发生的神经活动的持续性，将有可能检验神经持久性对于神经整合机制的运行至关重要的假设。通过使用选择性适应的方法，将有可能在20至540赫兹的刺激频率范围内测量时间总和。这些结果将检验兹维斯洛基(1960)的假说，该假说被提出来解释听力中的时间总和，即正弦刺激中的个别周期可以作为神经整合中的个别刺激事件。通过将正弦中的循环关联起来，可以在神经整合中充当单独的刺激事件。通过将时间求和、时间间隙检测和前向掩蔽的测量相关联，将可能确定神经持续性是否在对于时间求和是必要的时候降低了时间敏锐度并且扰乱了持续性，当对于时间求和是必要的时候是降低了时间敏锐度并且扰乱了在终止掩蔽刺激之后呈现的信号的可检测性。

The broad long-term goal of the project is to extend our knowledge of the temporal properties of sensory systems through an experimental study of vibrotactile temporal summation. By measuring psychophysical thresholds for detecting sinusoidal stimuli presented to the glabrous skin of the hand, the basic mechanisms of temporal integration should reveal themselves. The objective is to experimentally isolate the two possible fundamental mechanisms, probably summation and neural integration responsible for temporal summation in all sensory systems, and to define the conditions under which they operate in vibrotaction. By measuring psychophysical thresholds for detecting single and multiple-pulse stimuli when the level of and spectral characteristics of external background noise are manipulated it will be possible to test the hypothesis that probably summation in a sensory system requires a sufficient level of either internal or external noise so as to introduce a substantial amount of variability in the neural responses of the system, to repeated presentation of the same stimulus. By measuring thresholds for detecting multiple pulses separated by noise designed to disrupt the persistence of neural activity that could occur after termination of a stimulus, it will be possible to test the hypothesis that neural persistence is essential for the operation of the mechanism of neural integration. Through the use of a method of selective adaptation it will be possible to measure temporal summation over a range of stimulus frequencies from 20 to 540 Hz. The results will test Zwislocki's (1960) hypothesis, proposed to account for temporal summation in hearing, that individual cycles in a sinusoidal stimulus can serve as individual stimulus events in neural integration. By correlating cycles in a sinusoidal can serve as individual stimulus events in neural integration. By correlating measures of temporal summation, temporal gap detection and forward masking it will be possible to determine whether neural persistence, when necessary for temporal summation, reduces temporal acuity and disrupts the persistence, when necessary for temporal summation, reduces temporal acuity and disrupts the detectability of a signal presented after the termination of a masking stimulus.