Multimodally encoded spatial images in sighted and blind

描述(由申请人提供)：拟议的研究调查了在缺乏直接知觉支持的情况下用于指导行动的空间布局的表示。我们称其为“空间图像”。人类可以通过视觉、听觉和触觉感知周围的空间。环境对象和位置由特定于通道的“感知”在内部表示，只要它们受到来自视觉、听觉和触觉的同时感觉刺激的支持就存在。当这种刺激停止时，例如当眼睛闭上或关闭声源时，感知也就停止了。然而，在没有知觉的情况下，空间图像仍然存在。例如，当一个人看着一个物体，然后闭上眼睛，他就会体验到该物体在其感知指定的位置上的持续存在。虽然空间图像的现象学属性只有观察者才知道，但通过系统地研究观察者在空间更新等空间任务中的行为，可以揭示空间图像的功能特征。例如，观察者可能试图沿着各种路径中的任何一条盲目地走到先前查看的对象的位置。大量研究表明，人们拥有令人印象深刻的这样做的能力。空间图像的一个重要属性是，尽管输入的感觉通道不同，但在许多情况下它们的功能是相等的。在之前的工作中，PI已经表明，不同的输入方式，如视觉和听力，在各种空间任务中可以诱导同等的表现。也许更令人惊讶的是，研究发现，空间描述性语言产生的空间图像在功能上是相同的，或者几乎是相同的，就像空间任务中的表现所揭示的那样。我们的假设是，视觉、触觉、听觉和语言的不同空间形态都馈送到共同的非模态表征中。空间图像也可以通过从长期记忆中检索有关空间布局的信息来创建。重要的是，盲人能够执行许多空间任务，因为空间图像不限于视觉形式。尽管我们对空间图像的大部分理解来自实验室实验，这些实验似乎不能代表日常生活，但重要的是要认识到空间图像在视力正常和失明的人的生活中的普遍性。对于这两个群体来说，在许多情况下，保持紧邻周围环境的空间图像(例如，在办公室工作、进行运动)允许个人将他们的活动快速地重定向到对象上，而不必重新启动对它们的搜索。这会使动作变得流畅，只需很少的努力。我们提出的研究将进一步加深我们对视觉、触觉、听觉和语言输入产生的空间图像以及从长期记忆中提取空间信息所激活的空间图像的了解。我们的研究包括基于理论的实验，涉及有视力和盲人的受试者。所有的实验都依赖于逻辑来根据观察到的行为(如口头报告、操纵杆操纵)以及更复杂的空间动作(如伸手、指向和行走)来推断内部过程和表征。我们的实验分为3个主题。第一个主题是关于建立空间图像的进一步属性。在这个主题下的五个实验中，有四个是关于触觉和视觉是否产生了功能相似的空间图像；第五个实验将调查来自知觉的空间图像和来自长期记忆的空间图像之间可能的干扰。第二个主题中的五个实验采用了不同的范式和逻辑来测试来自不同感觉通道的空间图像是无模式的(不保留关于编码通道的信息)还是通道特有的(保留关于编码通道的信息)。第三个主题是关于空间图像是否在头部周围的所有方向上都同样精确，而视觉图像被认为只有在头部前面才具有高精度。这项研究的主要意义将是扩展多模式空间图像的知识，与视觉图像相比，到目前为止，多模式空间图像很少受到科学关注，已发表了数百篇关于视觉图像的科学论文。这一知识将进一步加深我们对视力正常和失明的人的空间认知相似程度的理解。这一知识对正在为盲人和视障人士开发包括导航系统在内的辅助技术的研究人员和技术人员也很有用。更广泛地说，这种知识将导致改进的空间认知测试，这将有助于更好地理解由阿尔茨海默氏症和脑损伤等疾病导致的知识和行为缺陷。

DESCRIPTION (provided by applicant): The proposed research investigates a representation of spatial layout that serves to guide action in the absence of direct perceptual support. We call this representation a "spatial image." Humans can perceive surrounding space through vision, hearing, and touch. Environmental objects and locations are internally represented by modality-specific "percepts" that exist as long as they are supported by concurrent sensory stimulation from vision, hearing, and touch. When such stimulation ceases, as when the eyes close or a sound source is turned off, the percepts also cease. A spatial image, however, continues to exist in the absence of the percept. For example, when one views an object and then closes the eyes, one experiences the continued presence of the object at its perceptually designated location. Although the phenomenological properties of the spatial image are known only to the observer, functional characteristics of spatial images can be revealed through systematic investigation of the behavior of the observer on a spatial task like spatial updating. For example, the observer might try to walk blindly to the location of a previously viewed object along any of a variety of paths. A sizeable body of research indicates that people have an impressive ability to do so. An important property of spatial images is that they function equivalently in many cases, despite variations in the input sensory modality. In previous work, the PI's have shown that distinct input modalities, like vision and audition, induce equivalent performance on a variety of spatial tasks. Perhaps even more surprising, spatially descriptive language was found to produce spatial images that are functionally equivalent, or nearly so, as revealed by performance on spatial tasks. Our hypothesis is that the different spatial modalities of vision, touch, hearing, and language all feed into a common amodal representation. Spatial images can also be created by retrieving information about spatial layout from long-term memory. Importantly, blind individuals are able to perform many spatial tasks because spatial images are not restricted to the visual modality. Although most of our understanding of spatial images comes from laboratory experiments that seem unrepresentative of everyday life, it is important to realize the pervasiveness of spatial images in the lives of sighted and blind people. For both populations, there are many circumstance where maintaining a spatial image of the immediately surrounding environment (e.g., working at the office, playing sports) allows individuals to rapidly redirect their activity to objects without having to re-initiate search for them. This leads to fluency of action with minimal effort. Our proposed research will further our knowledge about spatial images produced by visual, haptic, auditory, and language input as well as those activated by retrieval of spatial information from long-term memory. Our research consists of theoretically-based experiments involving sighted and blind subjects. All of the experiments rely on logic to make inferences about internal processes and representations from observed behavior, such as verbal report, joystick manipulation, and more complex spatial actions, like reaching, pointing, and walking. Our experiments are grouped into 3 topics. The first topic is concerned with establishing further properties of spatial images. Four of the five experiments under this topic are concerned with whether touch and vision produce spatial images that are functionally similar; the fifth will investigate possible interference between spatial images from perception and those from long-term memory. The five experiments within the second topic exploit different paradigms and logic for testing whether spatial images from different sensory modalities are amodal (retaining no information about the encoding modality) or modality-specific (retaining information about the encoding modality). The third topic is concerned with whether spatial images are equally precise in all directions around the head, in contrast to visual images which are thought to be of high precision only when located in front of head. The primary significance of this research will be the expansion of knowledge of multimodal spatial images, which so far have received very little scientific attention in comparison with visual images, about which hundreds of scientific papers have been published. This knowledge will further our understanding of the extent to which spatial cognition is similar in sighted and blind people. This knowledge will also be useful for researchers and technologists who are developing assistive technology, including navigation systems, for blind and visually impaired people. More generally, this knowledge will lead to improved tests of spatial cognition that will be useful in better understanding the deficits in knowledge and behavior resulting from diseases, such as Alzheimer's, and brain damage.