Uncovering the nature of object representations in the human dorsal visual cortex

揭示人类背侧视觉皮层中物体表征的本质

• 批准号: RGPIN-2019-06677
• 负责人: Freud, Erez
• 金额: $ 2.4万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716246
• 关键词: Uncovering; nature; object; representations; human

The human visual system enables us to recognize objects (e.g., this is a cup) and act upon them (e.g., grasp the cup) with astonishing ease and accuracy. For decades, it was widely accepted that these different functions rely on separated cortical pathways. In particular, the ventral pathway subserves object recognition, while the dorsal pathway subserves visually guided actions. However, recent evidence challenges this binary distinction and suggests that regions in the dorsal “action” pathway also derive shape representations that play a role in object perception. Despite this recent progress, the nature of shape representations derived by the dorsal pathway is still unclear. One major challenge in elucidating these representations is that they are modulated by a variety of factors, such as (a) the inputs from other brain regions, (b) task demands and (c) the physical features of the stimulus. Thus, the overarching goal of this research program is to shed light on the nature of dorsal shape representations by contemplating the extent to which different factors modulate these representations. In two complementary projects, we will address these questions, by utilizing a variety of state-of-the-art behavioural and neuroimaging techniques. The first project will examine whether independent shape representations are computed by the dorsal pathway, even when inputs from the ventral pathway are minimized. To this end, we will utilize experimental techniques which are designed explicitly to bias shape processing to the dorsal pathway. The main prediction is that despite the interconnections between the two pathways, the dorsal pathway derives independent shape representations. The second project will probe the degree to which task demands modulate dorsal shape representations. To that purpose, a variety of tasks, which require the processing of different shape attributes, will be employed, while the visual input will be kept constant. We predict that despite an automatic sensitivity of the dorsal pathway to shape information, dorsal representations will be modulated by task demands, particularly for tasks that involve spatial processing. Together, this research program has the potential to elucidate the neural underpinnings of shape perception, a fundamental perceptual ability. Moreover, these insights might shed light on the underlying mechanisms of congenital and acquired disorders in which visual perception is impaired.

人类的视觉系统使我们能够识别物体（例如，这是一个杯子），并以惊人的轻松和准确的方式对它们采取行动（例如，抓住杯子）。几十年来，人们普遍认为这些不同的功能依赖于分离的皮层通路。特别是，腹侧通路支持物体识别，而背侧通路支持视觉引导动作。然而，最近的证据挑战了这种二元区分，并表明背侧“动作”通路的区域也产生了在物体感知中起作用的形状表征。