Temporal Rate Adaption-Evidence for Supramodal Timing Mechanisms?

项目摘要 这项研究的长期目标是了解管理跨模式互动的原则 识别和表征超模式计时 感知速率的机制。核心假设是，存在一个强有力的、适应性强的中央时序 机制(对几秒到几分钟内的变化作出响应)，至少在一定程度上 统一的和多变的。拟议的研究将依赖于最近发现的跨模式后效，其中 重复暴露在脉冲适配器刺激下会导致对脉搏频率的感知发生变化 随后的刺激，使得相对较快的适配器导致较晚的刺激被感知为较慢，而 相对较慢的适配器则相反。即使在提供适配器和测试刺激的情况下也会发生这种情况 有不同的形式，从来不会一起呈现。在一系列心理物理实验中，这 将测试不同配置的单模、双模和跨模视觉刺激的效果。这些 实验将测量后效的强度和方向，因为它随不同的适配器刺激而变化 并且适配器和测试器之间具有不同的空间关系和速率差异。这些实验将 为超模式计时假说提供强有力的测试。一组额外的心理物理实验 将使用持续的闪光抑制来呈现参与者在很大程度上没有意识到视觉刺激和测试 适应是否仍在发生。这将决定效果是否需要有意识的意识(因此 可能在很大程度上是认知的)，或者至少部分是感知的。最后一组实验将使用脑电来 时间域。这项建议的具体目标是 跟踪 通过对功率谱的研究，确定了影响的时间频率范围和感知阈值 和稳态频率响应，并将提供一个客观的测量之间的因果关系 听觉和视觉网络在创造感知效果中的作用。这些实验的结果将放在 时间加工的神经元和计算模型的限制。时间错位被认为与 由于正常衰老以及阅读障碍、多动症、帕金森氏症、抑郁症、 和精神分裂症。大脑如何编码时间的更好模型有可能增强人们的理解 并可能对潜在的临床或心理干预产生影响。

Project Summary The long-term goal of this research is to understand the principles that govern crossmodal interactions in the identify and to characterize a supramodal timing mechanism for perception of rate. The central hypothesis is that there is a vigorous and adaptive central timing mechanism (responding to changes within the order of seconds to minutes) that is at least to some degree unified and amodal. The proposed studies will rely on a recently discovered crossmodal aftereffect in which repeated exposure to a pulsed adaptor stimulus leads to changes in the perception of the rate of pulsation of subsequent stimuli, such that a relatively fast adaptor leads to later stimuli being perceived as slower, while a relatively slow adaptor does the reverse. This happens even when the adaptor and test stimuli are presented with different modalities and are never presented together. In a series of psychophysical experiments, this effect will be tested with different configurations of unimodal, bimodal, and crossmodal visual stimuli. These experiments will measure the strength and direction of the aftereffect as it varies with different adaptor stimuli and with different spatial relationships and rate differences between adaptor and test. These experiments will provide for a strong test of the supramodal timing hypothesis. An additional set of psychophysical experiments will use continuous flash suppression to render participants are largely unaware of the visual stimuli and test whether adaptation still occurs. This will determine whether the effect requires conscious awareness (and thus may be largely cognitive) or is at least in part perceptual. A final set of experiments will use EEG to temporal domain. The specific objective of this proposal is to track the range of temporal frequencies and the perception threshold of the effect, via the study of the power spectrum and steady state frequency responses, and will provide an objective measure of the causal relationship between auditory and visual networks in creating the perceptual effect. The results of these experiments will place constraints on neuronal and computational models of temporal processing. Timing deficits have been linked to changes due to normal aging as well as to disorders including dyslexia, ADHD, Parkinson's disease, depression, and schizophrenia. A better model of how the brain encodes time has the potential to enhance understanding of these timing deficits and may have implications for potential clinical or psychological interventions.