Learning to see again: biological constraints on cortical plasticity and the implications for sight restoration technologies

摘要 视力恢复领域取得了戏剧性的进展：在十年内，许多盲人 个人可能会被提供广泛的视力恢复选择，这取决于 不同的技术，包括视网膜植入物、皮质植入物和光遗传学。 然而，植入物电子和潜在的神经生理学之间的相互作用 视网膜或皮质意味着这些技术中的大多数提供的视觉将有所不同 基本上与正常视线相距甚远。 皮质可塑性在帮助患者利用这种人工视觉方面起到了什么作用 投入？在过去的15年里，我们的研究小组一直在生成计算模型， 使用生理和心理物理数据的组合开发出来的，这些数据预测 患者可能会因各种视力恢复技术而体验到的感知。我们建议 要使用这些模型在视觉上正常的参与者中模拟关键的 多种视力恢复技术所固有的神经生理学失真：同时 刺激ON和OFF细胞。 我们的目标是了解这种失真输入的训练如何改变对象中的神经表征 选择性区域，如枕叶外侧皮质(LOC)。使用功能磁共振成像，我们将测量神经 对扭曲和未扭曲对象的反应，在使用扭曲输入的训练之前和之后。 一种可能性是，学习识别扭曲的对象会导致扭曲的对象图像 成为LOC中先前学习的神经表征的线索。另一种选择是， 这种训练的结果是在LOC中产生新的表示。这项工作将 通过提问提供关于皮质可塑性基本机制的新见解 在成年后，是否有可能重新配置视觉的基本构件 知觉？

ABSTRACT The field of sight restoration has made dramatic progress: within a decade, many blind individuals are likely to be offered a wide range of options for sight restoration that depend on widely different technologies, including retinal implants, cortical implants and optogenetics. However, interactions between implant electronics and the underlying neurophysiology of the retina or cortex mean that the vision provided by most of these technologies will differ substantially from normal sight. What role does cortical plasticity play in helping patients make use of this artificial visual input? Over the past 15 years our research group has been generating computational models, developed using a combination of physiological and psychophysical data, which predict the percepts that patients might experience for a variety of sight recovery technologies. We propose to use these models to simulate, within visually normal participants, a critical neurophysiological distortion inherent in many sight restoration technologies: the simultaneous stimulation of on and off cells. Our goal is to see how training with this distorted input alters neural representations in object selective areas such as lateral occipital cortex (LOC). Using fMRI, we will measure neural responses to distorted and undistorted objects, before and after training with distorted input. One possibility is that learning to recognize distorted objects results in distorted object images becoming cues for previously learned neural representations within LOC. The alternative is that this training results in the generation of novel representations within LOC. This work will provide novel insights regarding the fundamental mechanisms of cortical plasticity by asking whether, in adulthood, it is possible to reconfigure the fundamental building blocks of visual perception?