Ro Tony, Shelton Dominique, Lee Olivia L, Chang Erik
Department of Psychology, MS 25, Rice University, 6100 Main Street, Houston, TX 77005, USA.
Proc Natl Acad Sci U S A. 2004 Jun 29;101(26):9933-5. doi: 10.1073/pnas.0403061101. Epub 2004 Jun 21.
The proposed neural mechanisms supporting blindsight, the above-chance performance of cortically blind patients on forced-choice visual discrimination tasks, are controversial. In this article, we show that although subjects were unable to perceive foveally presented visual stimuli when transcranial magnetic stimulation over the visual cortex induced a scotoma, responses nonetheless were delayed significantly by these unconscious distractors in a directed saccade but not in an indirect manual response task. These results suggest that the superior colliculus, which is involved with sensory encoding as well as with the generation of saccadic eye movements, is mediating the unconscious processing of the transcranial magnetic stimulation-suppressed distractors and implicate a role of the retinotectal pathway in many blindsight phenomena.
关于支持盲视（即皮质盲患者在强制选择视觉辨别任务中表现超出预期）的神经机制存在争议。在本文中，我们表明，尽管当经颅磁刺激视觉皮层诱发暗点时，受试者无法感知中央凹呈现的视觉刺激，但在定向扫视任务中，这些无意识的干扰物仍会显著延迟反应，而在间接手动反应任务中则不会。这些结果表明，参与感觉编码以及眼球扫视运动生成的上丘，正在介导经颅磁刺激抑制的干扰物的无意识处理，并暗示视网膜 - 顶盖通路在许多盲视现象中发挥作用。
