深度学习: 智能时代的核心驱动力量

在去世之前，弗朗西斯·克里克还邀请我到他家中讨论屏状体（claustrum），这个皮层下的神秘细胞薄层接收来自许多皮层区域的投射，然后再反向投射回去。尽管克里克当时已身患绝症，但仍然专注于完成他的最后一篇论文，即屏状体因其中心地位而负责意识统一的假说。只有少数研究人员曾研究过屏状体，他几乎给他们中的每个人都打过电话，寻求进一步的信息。这次拜访是我最后一次见到他。弗朗西斯于2004年7月28日去世时，仍然在努力撰写他最后一篇论文^[24] 的手稿，试图完成他对意识起源的研究。

在他和詹姆斯·沃森于1953年发现DNA结构的50年后，人类基因组测序的项目完成了。克里克告诉我，他从来没有想过人类能够完成这一壮举。50年后，我们距离探清意识问题还有多远呢？届时，我们将拥有与我们互动的机器，就像我们现在通过语音、手势和面部表情与他人互动一样。创造意识要比完全理解它来得容易。

我怀疑，我们是否可以通过首先了解无意识的处理过程——我们看到、听到和行动时认为理所当然的一切——来加快进度。我们已经在理解激励系统方面取得了进展（激励系统对我们如何做决定产生了强烈的影响）；还有注意力系统（这些系统有助于指导我们在现实世界中搜寻信息）。随着对管理感知、决策和规划的大脑机制的深入了解，理解意识这个问题可能会像《爱丽丝漫游奇境记》中的柴郡猫一样消失，只留下一个大大的笑容。^[25]

1. 本章引自T. J. Sejnowski, “Consciousness,” Daedalus 144, no. 1 (2015): 123–132. 参阅Francis H. C. Crick, What Mad Pursuit: A Personal View of Scientific Discovery (New York: Basic Books, 1988): Bob Hicks, “Kindra Crick’s Mad Pursuit,” Oregon Art Watch , December 3, 2015.

   http://www.orartswatch.org/kindracricks-mad-pursuit/.

2. 现在还没有统一的关于“意识”（consciousness）的科学定义，意识被用来指代许多不同的现象。对这个术语广义上的理解，包括保持清醒的状态，对自己周围环境的认知，对事物的认知或感知，以及大脑对自身和外界的认知。
3. F. Crick, “The Function of the Thalamic Reticular Complex: The Searchlight Hypothesis,” Proceedings of the National Academy of Science of the United States of America 81, no. 14 (1984):4586–4590.
4. F. Crick and C. Koch, “The Problem of Consciousness,” Scientific American 267,no. 3 (1992): 10–17: F. Crick and C. Koch, “Constraints on Cortical and Thalamic Projections: The No-Strong-Loops Hypothesis,” Nature 391, no. 6664 (1998): 245–250: F. Crick and C. Koch, “A Framework for Consciousness,” Nature Neuroscience 6, no. 2 (2003): 119–126: and F. Crick, C. Koch, G. Kreiman, and I. Fried,“Consciousness and Neurosurgery,” Neurosurgery 55, no. 2 (2004): 273–281.
5. F. Crick and C. Koch, “Are We Aware of Neural Activity in Primary Visual Cortex?”Nature 375, no. 6527 (1995): 121–123: C. Koch, M. Massimini, M. Boly, and G.Tononi, “The Neural Correlates of Consciousness: Progress and Problems,” Nature Reviews Neuroscience 17 (2016): 307–321.
6. R. Q. Quiroga, L. Reddy, G. Kreiman, C. Koch, and I. Fried, “Invariant Visual Representation by Single Neurons in the Human Brain,” Nature 435, no. 7045(2005): 1102–1107.
7. 这种比例是通过对不同神经元的放电速率的比例来定量的。——译者注
8. K. Deisseroth and M. J. Schnitzer, “Engineering Approaches to Illuminating Brain Structure and Dynamics,” Neuron 80, no. 3 (2013): 568–577.
9. V. Mante, D. Sussillo, K. V. Shenoy, and W. T. Newsome, “Context-Dependent Computation by Recurrent Dynamics in Prefrontal Cortex,” Nature 503, no. 7474(2013): 78–84.
10. BRAIN Working Group, BRAIN 2025: A Scientiific Vision, Report to the Advisory Committee to the Director, NIH (Bethesda, MD: National Institutes of Health, June 5, 2014), 36.

    https://www.braininitiative.nih.gov/pdf/BRAIN2025_508C.pdf.

11. Patricia Smith Churchland and Terrence J. Sejnowski, The Computational Brain ,2nd ed.

    (Cambridge, MA: MIT Press, 2016), 183, 221.

12. L. Chang and D. Y. Tsao. “The Code for Facial Identity in the Primate Brain,” Cell 169, no. 6(2017): 1013–1028.e14.
13. D. A. Bulkin and J. M. Groh, “Seeing Sounds: Visual and Auditory Interactions in the Brain,” Current Opinion in Neurobiology 16 (2006): 415–419.
14. 闪光滞后幻觉表现为主体对突现客体的位置判断滞后。——译者注
15. D. M. Eagleman and T. J. Sejnowski, “Motion Integration and Postdiction in Visual Awareness,” Science 287, no. 5460 (2000): 2036–2038.
16. 参阅Stephen L. Macknik, Susana Martinez-Conde, and Sandra Blakeslee, Sleights of Mind: What the Neuroscience of Magic Reveals about Our Everyday Deceptions (New York: Henry Holt,2010)。
17. S. Dehaene and J.-P. Changeux, “Experimental and Theoretical Approaches to Conscious Processing,” Neuron 70, no. 2 (2011): 200–227.
18. S. Moeller, T. Crapse, L. Chang, and D. Y. Tsao, “The Effect of Face Patch Microstimulation on Perception of Faces and Objects,” Nature Neuroscience 20, no. 6(2017): 743–752.
19. J. Parvizi, C. Jacques, B. L. Foster, N. Withoft, V. Rangarajan, K. S. Weiner, and K.Grill-Spector, “Electrical Stimulation of Human Fusiform Face-Selective Regions Distorts Face Perception,” Journal of Neuroscience 32, no. 43 (2012): 14915–14920.
20. BRAIN Working Group, BRAIN 2025: A Scientific Vision , pp. 6, 35, 48.
21. Sejnowski, “What Are the Projective Fields of Cortical Neurons?”
22. L. Chukoskie, J. Snider, M. C. Mozer, R. J. Krauzlis, and T. J. Sejnowski, “Learning Where to Look for a Hidden Target,” Proceedings of the National Academy of Sciences of the United States of America 110, supp. 2 (2013): 10438–10445.
23. T. J. Sejnowski, H. Poizner, G. Lynch, S. Gepshtein, and R. J. Greenspan,“Prospective Optimization,” Proceedings of the IEEE 102, no. 5 (2014): 799–811.
24. 在他去世后，他的同事克里斯托弗·科赫（Christof Koch）继续完成了这项工作。F. C. Crick and C. Koch, “What Is the Function of the Claustrum?”Philosophical Transactions of the Royal Society of London B360, no. 1458 (2005),1271–1279.
25. 参阅Lewis Carroll, Alice ’s Adventures in Wonderland (London: Macmillan,1865), chap. 6.