Haefner Ralf M, Cumming Bruce G
Laboratory for Sensorimotor Research, National Eye Institute/NIH, 49 Convent Drive, Building 49/2A50, Bethesda MD 20892, USA.
Neuron. 2008 Jan 10;57(1):147-58. doi: 10.1016/j.neuron.2007.10.042.
Sensory processing in the brain is thought to have evolved to encode naturally occurring stimuli efficiently. We report an adaptation in binocular cortical neurons that reflects the tight constraints imposed by the geometry of 3D vision. We show that the widely used binocular energy model predicts that neurons dedicate part of their dynamic range to impossible combinations of left and right images. Approximately 42% of the neurons we record from V1 of awake monkeys behave in this way (a powerful confirmation of the model), while about 58% deviate from the model in a manner that concentrates more of their dynamic range on stimuli that obey the constraints of binocular geometry. We propose a simple extension of the energy model, using multiple subunits, that explains the adaptation we observe, as well as other properties of binocular neurons that have been hard to account for, such as the response to anti-correlated stereograms.
大脑中的感觉处理被认为已经进化到能够有效地编码自然发生的刺激。我们报告了双目皮层神经元中的一种适应性变化，它反映了三维视觉几何结构所施加的严格限制。我们表明，广泛使用的双目能量模型预测，神经元会将其动态范围的一部分用于处理左右图像的不可能组合。我们从清醒猴子的V1区记录的神经元中，约42%以这种方式表现（这有力地证实了该模型），而约58%则以一种将其更多动态范围集中在符合双目几何结构限制的刺激上的方式偏离该模型。我们提出了一种使用多个亚基的能量模型的简单扩展，它解释了我们观察到的适应性变化，以及双目神经元的其他难以解释的特性，比如对反相关立体图的反应。
