Spatial Representations of Depth: Do Cognitive Maps Facilitate Depth Perception?

自从发现位置和网格细胞以来，海马体和内嗅觉皮质已经成为认知地图的震中，认知地图是动物局部环境的神经表征。后来对编码头部方向、速度、方向、显著地标和环境边界的细胞的发现，都进一步促进了我们对认知地图及其在大脑中的排列的更复杂的理解。尽管有这些发现，大脑如何接收局部感觉输入并将其转换为可解释的神经信号，从而影响感知和行为，仍然知之甚少。目前的啮齿动物行为研究主要涉及使用一个空的围栏，很少包括野外丰富的航行所必需的当地地标。最近的研究表明，局部环境几何形状的扭曲会损害大鼠的航行，并产生相应的网格元胞磁场扭曲，因此在空间推理的背景下理解环境、物理感觉和意识知觉之间的关系是至关重要的。本博士项目旨在将啮齿动物电生理学和人类心理物理学相结合，通过研究环境线索变化对知觉的影响来探索空间认知和视觉知觉之间的关系。通过在动物行为学测试中对海马区和内侧嗅皮层(MEC)细胞的在体电生理记录，研究环境扭曲和局部地标变化对空间推理能力的影响。此外，转基因动物品系将被用来探索神经发生和认知图谱中涉及的特定结构在环境神经编码中的作用，特别是MEC进入齿状回和海马区的第二层输出。对啮齿动物任务中人类深度知觉的相应研究将为视觉感知和环境连续性在人类空间认知中的作用提供翻译洞察力。

Since the discovery of place and grid cells, the hippocampus and entorhinal cortex have become the epicentre for the cognitive map, a neural representation of an animal's local environment. Subsequent discoveries of cells which code for head direction, speed, orientation, salient landmarks, and environmental boundaries have all further contributed to our ever more complex understanding of the cognitive map and its arrangement in the brain.Despite these discoveries, how the brain receives allocentric sensory inputs and converts them into interpretable neural signals which effect perception and behaviour is still poorly understood. Present rodent behavioural research primarily involves the use of an empty enclosure with little inclusion of the local landmarks essential for navigation that are abundant in the wild. With recent research showing that distortions in local environmental geometry can impair navigation in rats and produce corresponding distortion of the grid cell field, understanding the relationship between the environment, physical sensation, and conscious perception in the context of spatial reasoning is of paramount importance.This PhD project aims to combine rodent electrophysiology and human psychophysics to explore the relationship between spatial cognition and visual perception by investigating how perception is influenced by changing environmental cues. Through the use of in vivo electrophysiological recording of cells in the hippocampus and medial entorhinal cortex (MEC) during animal behavioural testing, the effect of environmental distortion and changing local landmarks on spatial reasoning ability will be investigated. Additionally, transgenic animal lines will be used to explore the role of neurogenesis and specific structures involved in the cognitive map in neural coding for the environment, particularly the layer II output of the MEC into the dentate gyrus and hippocampus. A corresponding study of human depth perception adapted from the rodent tasks will provide translational insights into the role of visual perception and environmental continuity in human spatial cognition.