Bistable Percepts in the Brain: fMRI Contrasts Monocular Pattern Rivalry and Binocular Rivalry
Bistable Percepts in the Brain: fMRI Contrasts Monocular Pattern Rivalry and Binocular Rivalry
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DOI：
10.1371/journal.pone.0020367
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发表时间：
2011-05-23
期刊：
影响因子：
3.7
通讯作者：
Mendola, Janine D.
中科院分区：
文献类型：
--
作者：
Buckthought, Athena;Jessula, Samuel;Mendola, Janine D.
近年来，双眼竞争的神经相关性一直受到积极的争论，并且由于它们可能揭示意识意识的机制而引起了相当大的兴趣。在一个相关的现象，单眼竞争，一个复合图像显示给两只眼睛。受试者经历知觉交替，其中两个刺激成分在清晰度或显著性上交替。的经验是类似的知觉交替在双眼竞争，虽然减少的能见度的抑制组件是更大的双眼竞争，特别是在较高的刺激对比度。我们使用功能磁共振成像在3 T图像活动的视觉皮层，而受试者认为无论是单眼或双眼竞争，或匹配的非竞争性控制条件。刺激模式为左/右倾斜光栅，亮度对比度设置为9%、18%或36%。与空白屏幕相比，双眼和单眼竞争都显示出U形激活函数作为刺激对比度的函数，即在9%和36%的大部分区域具有更高的活性。单眼竞争的皮层激活部位包括枕极（V1，V2，V3），腹侧颞叶和上级顶叶皮层。双眼竞争的其他区域包括外侧枕区，以及靠近颞顶交界处（TPJ）的下顶叶皮质。特别是，高层地区MT+和V3 A更活跃的双眼比单眼竞争的所有对比。相比之下，在V2和V3的激活减少双眼相比，单眼竞争在较高的对比度，引起更强的双眼知觉抑制，表明抑制的影响并不限于眼间抑制V1。
The neural correlates of binocular rivalry have been actively debated in recent years, and are of considerable interest as they may shed light on mechanisms of conscious awareness. In a related phenomenon, monocular rivalry, a composite image is shown to both eyes. The subject experiences perceptual alternations in which the two stimulus components alternate in clarity or salience. The experience is similar to perceptual alternations in binocular rivalry, although the reduction in visibility of the suppressed component is greater for binocular rivalry, especially at higher stimulus contrasts. We used fMRI at 3T to image activity in visual cortex while subjects perceived either monocular or binocular rivalry, or a matched non-rivalrous control condition. The stimulus patterns were left/right oblique gratings with the luminance contrast set at 9%, 18% or 36%. Compared to a blank screen, both binocular and monocular rivalry showed a U-shaped function of activation as a function of stimulus contrast, i.e. higher activity for most areas at 9% and 36%. The sites of cortical activation for monocular rivalry included occipital pole (V1, V2, V3), ventral temporal, and superior parietal cortex. The additional areas for binocular rivalry included lateral occipital regions, as well as inferior parietal cortex close to the temporoparietal junction (TPJ). In particular, higher-tier areas MT+ and V3A were more active for binocular than monocular rivalry for all contrasts. In comparison, activation in V2 and V3 was reduced for binocular compared to monocular rivalry at the higher contrasts that evoked stronger binocular perceptual suppression, indicating that the effects of suppression are not limited to interocular suppression in V1.