Ambiguous scraps of sense data

A note for Lesson no. 4, "Your Brain Predicts (Almost) Everything You Do," in Seven and a Half Lessons About the Brain by Lisa Feldman Barrett.
Some context from page 66 is:

Faced with these ambiguous scraps of sense data, your brain must somehow figure out what to do next.

The appendix adds:

Sense data is not only ambiguous but also incomplete.

A lot of sense data about the world and the body is lost when it is transduced in the sensors (i.e., the retina, the cochlea, etc.) and makes its way to the brain. Scientific estimates might be disagree by a factor of 10 but everyone agrees that neurons convey less info from the world than is out there. For example, the retina throws away a considerable amount of visual information.[1][2] So how do we see what is in the world? The brain infers what is missing — it can reconstruct it, infer it, can guess it, based on what it takes in. Much of the brain is reconstructing/reassembling the visual information that was useful in the past to construct what you see. There is an advantage to this: it allows your brain to bring wisdom to your perceptions -- your brain brings more information to every decision than just what you are able to sense in the actual input – historical inputs that you have encountered before – a past that is tailored to a specific set of circumstances in your culture or your personal experience.

In addition, when a brain infers the missing input, it does so in a way that is informed by the other senses (e.g., the visceral systems in your body are helping your brain figure out what is important and what is not (what is signal and what is noise).[3][4]

Also see Andy Clark's Surfing Uncertainty.[5]


  1. Meister, Markus, and Marc Tessier-Lavigne. 2013. "Low Level Visual Processing: The Retina" In Principles of Neural Science, edited by Eric R. Kandel, James H. Schwartz, Thomas M. Jessell, Steven A. Siegelbaum, and A.J. Hudspeth, 577–601. New York: McGraw Hill Medical.
  2. Wandell, Brian A. 1995. Foundations of Vision. Sunderland, MA: Sinauer Associates.
  3. Tallon-Baudry, Catherine, Florence Campana, Hyeong-Dong Park, and Mariana Babo-Rebelo. 2018. "The Neural Monitoring Of Visceral Inputs, Rather Than Attention, Accounts For First-Person Perspective In Conscious Vision." Cortex 102: 139–149.
  4. Allen, Micah, Andrew Levy, Thomas Parr, and Karl J. Friston. 2019. "In the Body's Eye: The Computational Anatomy of Interoceptive Inference." BioRxiv: 603928.
  5. Clark, Andy. 2015. Surfing Uncertainty: Prediction, Action, and the Embodied Mind. New York: Oxford University Press.