Montreal Neurological Institute and Department of Neurology and Neurosurgery, McGill University, Montreal, H3A2B4, Canada; Psychology Department, McGill University, Montreal, H3A2B4, Canada.
Montreal Neurological Institute and Department of Neurology and Neurosurgery, McGill University, Montreal, H3A2B4, Canada.
Curr Biol. 2018 Oct 22;28(20):R1184-R1186. doi: 10.1016/j.cub.2018.09.006.
Normal vision requires the classic neural pathway from retina to lateral geniculate nucleus (LGN) to cortex. A lesion of visual cortex causes blindness, but often unconscious visual abilities are retained; this is known as 'blindsight' and is characterised by responses to visual stimuli a patient denies seeing. Three types of blindsight have been proposed: action blindsight, attention blindsight and agnosopsia [1]. Here we study action blindsight - motor responses to unseen stimuli - via the influence on eye saccades of a visual stimulus presented in a blind area. One pathway that hypothetically enables action blindsight in humans, but that has never been formally proven to do so, is the primitive retino-tecto-reticular pathway. We demonstrate, in hemidecorticate patients with no available neural structures for vision on one side except for the primitive retino-tecto-reticular pathway, that saccades to their blind hemifield can be perturbed by an unseen visual probe according to visuo-motor interactions on the logarithmically-encoded motor map of their superior colliculus (SC) [2]. The primitive retino-tecto-reticular pathway thus appears to be functional in these patients.
正常视觉需要经典的神经通路，从视网膜到外侧膝状体核（LGN）再到皮层。视皮层的损伤会导致失明，但通常会保留无意识的视觉能力；这被称为“盲视”，其特征是患者否认看到的视觉刺激的反应。已经提出了三种类型的盲视：动作盲视、注意盲视和失认症[1]。在这里，我们通过在盲区呈现视觉刺激来研究看不见的刺激的动作盲视——即眼跳的影响。在人类中，有一种假设的通路可以实现动作盲视，但从未被正式证明可以实现，即原始的视网膜-顶盖-网状通路。我们证明，在半脑切除的患者中，除了原始的视网膜-顶盖-网状通路外，一侧没有用于视觉的神经结构，根据他们上丘的对数编码运动图上的视动相互作用，可以根据看不见的视觉探针干扰他们的盲侧视野的眼跳[2]。因此，在这些患者中，原始的视网膜-顶盖-网状通路似乎是功能性的。
