Non-canonical binocular pathways in human vision

人类视觉中的非规范双眼通路

• 批准号: BB/V007580/1
• 负责人: Daniel Baker
• 金额: $ 75.93万
• 依托单位: University of York
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FV007580%2F1
• 关键词: Non; canonical; binocular; pathways; human

The human brain combines information from many sources, including across our two forward-facing eyes with overlapping visual fields. This results in a single image of the external world, and provides us with stereo (3D) vision. But the brain also combines information across the eyes for several other reasons. One example is the response of our pupils to changes in light levels - the brain must use light levels from both eyes to decide how much to dilate or constrict the pupils. This happens in a completely different network of brain regions to those involved in perception. Separately, studies in animals have found a direct pathway to motion-sensitive regions of the brain, that may govern automatic eye movements to fast moving objects. Although we know about the anatomy of these other binocular pathways, we understand much less about precisely what they are doing. This project aims to understand the computations involved, and to compare them to those in the perceptual pathway, which are better understood, and for which mathematical models already exist.To achieve this, we will perform experiments in human volunteers. Our first study will focus on the pathway that governs pupil diameter. We can measure how the pupils constrict and dilate in response to flickering lights by using an eye-tracker. These responses can be compared to the responses of the perceptual parts of the brain, which we measure at the same time using EEG (a technique that records electrical brain activity at the scalp). Our visual system involves multiple 'colour channels', that are fed by cells in the eye that respond to different wavelengths of light. Some of these appear to be more important than others for deciding the pupil response, so we will compare the characteristics of binocular combination across the different channels. We will also look at whether the channels interact across the eyes, e.g. if we show light of different wavelengths to the left and right eyes, how does activity in the different colour channels interact?Next, we will investigate the operation of the pathway that governs automatic eye movements to moving objects. The anatomical pathways involved may be directly activated by specific wavelengths of light (blue coloured light, that activates the S-cone pathway). By measuring eye movements in response to fast moving stimuli presented to one or both eyes, targeted towards a particular colour pathway, we can directly assess the contribution of different channels in this calculation. We will also measure brain activity directly, again using EEG, to help us understand the timecourse of the neural operations that govern binocular eye movement planning. We will also repeat some of the above experiments in patients with amblyopia, a disorder of binocular vision in which one eye contributes much less to vision than the other. Although we know much about the consequences of amblyopia for perception, it may be that other binocular pathways remain unaffected. Understanding this will aid the development of treatments for this condition in the future.A final study will use state-of-the art brain scanners (MRI and MEG) to measure the response of the brain to images shown to either one or two eyes, using a 3D projector. In the perceptual regions of the brain, the increased response when both eyes are open is balanced by a process of suppression between the eyes. This means that the brain activity is about the same whether one or both eyes see the stimulus, consistent with our everyday observation that the world does not change in appearance when two eyes are open compared to one. But we suspect that in the other binocular pathways, there might be a much bigger increase when both eyes are stimulated. So, we will look for brain regions that give a larger response to binocular stimulation than to monocular stimulation. We will do this for a range of different stimuli that are designed to target specific pathways (e.g. the motion pathway).

人类大脑结合了许多来源的信息，包括我们两只具有重叠视野的前向眼睛的信息。这会产生外部世界的单一图像，并为我们提供立体 (3D) 视觉。但出于其他几个原因，大脑也会结合眼睛的信息。一个例子是我们的瞳孔对光线水平变化的反应 - 大脑必须利用双眼的光线水平来决定瞳孔扩张或收缩的程度。这种情况发生在与参与感知的大脑区域完全不同的网络中。另外，对动物的研究发现了一条通往大脑运动敏感区域的直接通路，该通路可能控制眼睛对快速移动物体的自动运动。尽管我们了解这些其他双眼通路的解剖结构，但我们对它们到底在做什么却知之甚少。该项目旨在了解所涉及的计算，并将它们与感知路径中的计算进行比较，这些计算更好地理解，并且数学模型已经存在。为了实现这一目标，我们将在人类志愿者中进行实验。我们的第一项研究将重点关注控制瞳孔直径的途径。我们可以使用眼动仪测量瞳孔如何响应闪烁的灯光而收缩和扩张。这些反应可以与大脑感知部分的反应进行比较，我们同时使用脑电图（一种记录头皮脑电活动的技术）来测量大脑感知部分的反应。我们的视觉系统涉及多个“颜色通道”，这些通道由眼睛中对不同波长的光做出反应的细胞提供能量。其中一些对于决定瞳孔反应似乎比其他更重要，因此我们将比较不同通道的双眼组合的特征。我们还将研究通道是否在眼睛之间相互作用，例如眼睛。如果我们向左眼和右眼显示不同波长的光，不同颜色通道的活动如何相互作用？接下来，我们将研究控制眼球自动运动到移动物体的路径的操作。所涉及的解剖通路可能会被特定波长的光（蓝色光，激活 S 锥体通路）直接激活。通过测量针对一只或两只眼睛呈现的快速移动刺激的眼球运动，针对特定的颜色路径，我们可以直接评估不同通道在此计算中的贡献。我们还将再次使用脑电图直接测量大脑活动，以帮助我们了解控制双眼眼球运动计划的神经操作的时间过程。我们还将在弱视患者身上重复上述一些实验，弱视是一种双眼视觉障碍，其中一只眼睛对视力的贡献远小于另一只眼睛。尽管我们对弱视对感知的影响了解很多，但其他双眼通路可能不受影响。了解这一点将有助于将来开发针对这种情况的治疗方法。最终研究将使用最先进的脑部扫描仪（MRI 和 MEG）来测量大脑对向一只或两只眼睛显示的图像的反应，使用 3D 投影仪。在大脑的感知区域中，双眼睁开时增加的反应通过眼睛之间的抑制过程来平衡。这意味着无论一只眼睛还是两只眼睛看到刺激，大脑活动都大致相同，这与我们日常观察一致，即与一只眼睛相比，睁开两只眼睛时世界的外观不会发生变化。但我们怀疑，在其他双眼通路中，当双眼受到刺激时，可能会有更大的增加。因此，我们将寻找对双眼刺激比对单眼刺激做出更大反应的大脑区域。我们将对一系列旨在针对特定路径（例如运动路径）的不同刺激进行此操作。

项目成果

Different rules for binocular combination of luminance flicker in cortical and subcortical pathways

皮层和皮层下通路中亮度闪烁的双眼组合的不同规则

• DOI: http://dx.10.1101/2023.01.11.523568
• 发表时间: 2023
• 作者: Segala F

Different rules for binocular combination of luminance flicker in cortical and subcortical pathways.

皮层和皮层下通路中亮度闪烁的双眼组合的不同规则。

• DOI: http://dx.10.7554/elife.87048
• 发表时间: 2023
• 期刊: eLife
• 影响因子: 7.7
• 作者: Segala FG

Distinct neural signatures of multimodal resizing illusions.

多模式调整大小错觉的独特神经特征。

• DOI: http://dx.10.1016/j.neuropsychologia.2023.108622
• 发表时间: 2023
• 期刊: Neuropsychologia
• 影响因子: 2.6
• 作者: Hansford KJ

PySilSub: An open-source Python toolbox for implementing the method of silent substitution in vision and nonvisual photoreception research.

PySilSub：一个开源 Python 工具箱，用于在视觉和非视觉感光研究中实现无声替换方法。

• DOI: http://dx.10.1167/jov.23.7.10
• 发表时间: 2023
• 期刊: Journal of vision
• 影响因子: 1.8
• 作者: Martin JT

Poster Session I: Binocular facilitation of the BOLD response to melanopsin stimulation in the suprachiasmatic nucleus

海报会议 I：双眼促进视交叉上核黑视蛋白刺激的 BOLD 反应

• DOI: http://dx.10.1167/jov.23.15.27
• 发表时间: 2023
• 期刊: Journal of Vision
• 影响因子: 1.8
• 作者: Martin J