Stimulus and context effects on perception

视觉系统的主要目标之一是识别物体，以便我们可以与它们进行适当的交互。虽然对人、地点和事物的识别通常看起来毫不费力和瞬间，但感知需要可测量的时间，视觉系统必须克服巨大的障碍才能识别。例如，到达我们眼睛的原始图像的各种元素必须被适当地组织，以便我们感知连贯的，有意义的，完整的对象，而不是不适当地分割，令人困惑的场景。考虑到识别过程的复杂性，我们对识别背后的神经机制知之甚少也就不足为奇了。目前的建议的目的是推进这种理解，特别是在刺激和上下文信息的作用，对面孔的视觉感知。在过去的十年里，我的实验室已经完善了许多心理物理和电生理技术，使我们能够在不同的层面上解决这些问题。目前的建议扩展了这项工作，特别是在理解面部识别的神经机制方面，并分支到新的领域，研究视觉感知的各个方面是如何被上下文线索和经验改变的。虽然我的工作依赖于行为技术来推断潜在的神经过程，但我也利用了融合方法-将现代心理物理学方法与神经成像技术（如脑电图）相结合。我的行为研究将利用心理物理的歧视任务，以确定一个刺激观察者在识别和区分面孔使用的确切方面。我还将介绍这些行为指标如何与神经活动相关，包括N170和N250（ERP中面部感知的两个关键标志），以及使用一系列统计方法的EEG信号的更广泛元素，我们已经改进了这些方法，以了解个体观察者和个体试验水平上的大脑行为相互作用。这些研究的结果将提供关于大脑如何处理面部和其他物体信息的见解;将确定行为和神经处理的哪些方面是稳定的，哪些是可塑的，基于学习和上下文;并将增强我们对感官信息如何跨模态组合的理解。虽然该研究项目侧重于基础科学问题，但其结果可能为人工视觉系统的开发和增强面部感知的神经技术提供见解。该研究计划还将为众多学员提供优秀的培训，使他们具备科学知识和专业，研究和沟通技能，以在未来的职业生涯中取得成功。

One of the main goals of the visual system is to recognize objects so that we may interact with them appropriately. Although recognition of people, places, and things typically appears effortless and instantaneous, perception takes measurable time, and the visual system must overcome tremendous obstacles for recognition to occur. For example, various elements of the raw images that reach our eyes must be organized appropriately, so that we perceive coherent, meaningful, complete objects rather than inappropriately segmented, confusing scenes. Given the complexity of the recognition process, it is not surprising that we have relatively little understanding of the neural mechanisms underlying recognition. The objective of the current proposal is to advance that understanding, particularly with respect to the role of stimulus and contextual information on the visual perception of faces. Over the past decade, my lab has refined a number of psychophysical and electrophysiological techniques that enable us to address these issues at different levels than previously possible. The current proposal extends this work, especially with respect to understanding the neural mechanisms underlying face recognition, and branches into new areas examining how aspects of visual perception are altered by contextual cues and experience. Although my work relies on behavioural techniques to make inferences about underlying neural processes, I also make use of converging methodologies -- combining modern psychophysical approaches with neuroimaging techniques, such as electroencephalography. My behavioural research will utilize psychophysical discrimination tasks to identify the precise aspect of a stimulus observers use in recognizing and discriminating faces. I also will how these behavioural measures correlate with neural activity, including the N170 and N250 (two key markers of face perception within the ERP), but also broader elements of the EEG signal using a range of statistical approaches we have refined to understand brain-behaviour interactions at the level of the individual observer and the individual trial. The results of these studies will provide insight into how the brain processes information about faces and other objects; will determine which aspects of behaviour and neural processing are stable, and which are malleable, based on learning and context; and will enhance our understanding of how sensory information is combined across modalities. Although the research program focuses on fundamental scientific issues, results may provide insights for the development of artificial vision systems, and neurotechnologies to enhance face perception. The research program also will provide excellent training for numerous trainees, equipping them with the scientific knowledge and professional, research, and communication skills to succeed in their future careers as researchers.**