Effects of category learning on visual representations

类别学习对视觉表征的影响

• 批准号: 7806743
• 负责人: Jonathan R Folstein
• 金额: $ 5.05万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-01 至 2011-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7806743
• 关键词: Accounting; Agnosia; Autistic Disorder; Behavior; Behavioral; Biological Neural Networks; Brain; Categories; Characteristics; Code; Color; Complex; Diagnostic; Dimensions; Dyslexia; Family; Functional Magnetic Resonance Imaging; Future; Human; Investigation; Learning; Literature; Maps; Measures; Modeling; Motion; Neuronal Plasticity; Neurons; Pattern; Process; Property; Role; Scanning; Series; Shapes; Stimulus; Stretching; Structure; Techniques; Time; Training; Visual; Visual Cortex; Work; base; executive function; experience; flexibility; neural patterning; neural prosthesis; psychologic; relating to nervous system; research study; skills

DESCRIPTION (provided by applicant): How do visual representations of objects change with experience? While it is now widely acknowledged that visual representations change with experience, questions abound concerning the time-course, flexibility, and degree to which experience can change object representations. Objects can be represented psychologically as points in the space of dimensions on which they vary (e.g., color, shape, manner of motion). The central hypothesis of this proposal is that some dimensions of objects can be enhanced by experience categorizing those objects. We will consider under the same conceptual umbrella a number of phenomena and mechanisms that represent cases of such dimensional modulation, so that they can be compared and integrated in a unified framework. The first aim is to seek evidence for dimensional modulation in visual cortex with category learning. There is some controversy over whether categorization experience influences visual cortical representations. Resolving this controversy is essential to fully understand experience- dependent neural plasticity in visual cortex. The second aim is to study the neural basis of both flexible and stable dimensional modulation. Flexible dimensional modulation is often characterized as a top-down influence on visual representations through executive control, while stable dimensional modulation is instead characterized as a bottom-up change in the underlying perceptual representations. This work aims to clarify how top-down and bottom-up influences shape experience-dependent neural plasticity in visual cortex. We vary task demands, the amount of learning, types of stimulus dimensions, and category structures to explore the multiple facets of dimensional modulation caused by category learning, both behaviorally and using fMRI. Our fMRI work uses a combination of two complementary techniques for measuring differences within overlapping neural networks, release from repetition suppression and multivoxel pattern analysis. Our work will provide an opportunity to use converging evidence from the two techniques, comparing their strengths and weaknesses within the same study. Ultimately, an understanding of the plasticity of the neural code in visual cortex has important implications for understand deficits in fine perceptual skills seen in dyslexia, autism, and visual agnosia, and for creating future neural prosthetics that interface directly the human brain by interpreting patterns of neural firing.

描述（由申请人提供）：对象的视觉表示如何随经验而变化？虽然现在广泛地承认，视觉表示会随经验而变化，但有关时间表，灵活性和体验可以改变对象表示的问题的问题。物体可以在心理上表示为它们变化的维度（例如颜色，形状，运动方式）的点。该提议的中心假设是，可以通过对这些对象进行分类来增强对象的某些维度。我们将在相同的概念保护伞下考虑代表这种维度调制案例的许多现象和机制，以便可以将它们进行比较和整合到统一的框架中。第一个目的是寻求通过类别学习的视觉皮层调制的证据。关于分类经验是否会影响视觉皮质表示，存在一些争议。解决这一争议对于完全理解视觉皮层中经验依赖的神经可塑性至关重要。第二个目的是研究灵活和稳定尺寸调节的神经基础。灵活的维度调制通常被表征为通过执行控制对视觉表示的自上而下的影响，而稳定的维度调制则将其特征在于基础感知表示的自下而上的变化。这项工作旨在阐明自上而下和自下而上的影响视觉皮层中的形状依赖体验的神经可塑性。我们改变了任务要求，学习量，刺激维度的类型和类别结构，以探索由类别学习引起的多个方面的多个方面，无论是在行为上还是使用fMRI。我们的功能磁共振成像工作结合了两种互补技术，以衡量重叠的神经网络中的差异，从重复抑制和多毒素模式分析中释放。我们的工作将为使用两种技术的融合证据提供机会，比较它们在同一研究中的优势和劣势。最终，对视觉皮层中神经代码的可塑性的理解对了解阅读障碍，自闭症和视觉不适的良好感知技能缺陷以及创建未来的神经假体，从而通过解释神经射击模式直接接触人脑的缺陷具有重要意义。