I have read in some websites that the percentage of the cortex devoted to processing visual information is from 30-66% with some claiming even 90%. And compared to that, only about 3% is dedicated to hearing.

Is this true?

The only source I've found stating something similar is from Sells & Fixott (1957) where 50% of the neural tissue is devoted to vision and almost two-thirds of the electrical activity of the brain is devoted to vision when the eyes are open.

I haven't found anything related to hearing though. Does anyone know of a paper where this is discussed?


Sells, S.B. & Fixott, R. S. (1957). Evaluation of Research on Effects of Visual Training on Visual Functions. American Journal of Ophthalmology 44(2), 230—236
DOI: 10.1016/0002-9394(57)90012-0

  • 1
    $\begingroup$ It is interesting that there are plenty of quotes for the Fixot paper, but no information on what the paper was titled or DOI. Just "Fixot, RS. American Journal of Ophthalmology; 1957". I even did a search on the AJO Website with no success. Is this a genuine quote or is everyone just repeating a false quote with a false citation? $\endgroup$ Mar 1, 2018 at 22:52
  • $\begingroup$ Ah, Bowen, (2012) gives us the month of August for publication date. I did a manual search and found it. I couldn't find the information cited though. Maybe I am missing something. Full citation will be added by editting $\endgroup$ Mar 1, 2018 at 23:06
  • $\begingroup$ I had exactly the same issue. Have you found anything on the hearing claim? $\endgroup$
    – Girauder
    Mar 2, 2018 at 9:18
  • $\begingroup$ The closest I can see is "not over 50 percent of the variance in visual acuity was accounted for by structural, optic, and anatomic factors reflected in the retinoscopic refraction." Not being an expert in this field, I am not sure this backs the statements made by others. $\endgroup$ Mar 2, 2018 at 11:18
  • $\begingroup$ The claim in usually that 90% of our sensory information/perception is from vision, not that 90% of cortex in devoted to vision. $\endgroup$ Mar 2, 2018 at 15:16

1 Answer 1

  1. 20-30% vision. See Sheth & Young (2016) which cites Van Essen (2003).
  2. 27% vision, 8% auditory (Van Essen, 2003)
  3. I have seen some earlier references that say 50%. I think this derives from two factors. First, it is 50% in Macaque (see above ref 1). Second, my feeling (I haven't dug into this in enough detail to conclusively state it, so please don't quote me on this!) is that earlier studies on humans were more speculative and tended to follow that 50% as a best guess in absence of direct measurements.
  4. As some of the above answers point out, one needs to be careful in defining what part of the brain and what vision means. If one were to include the subcortical structures (i.e., amygdala, superior colliculus, pulvina, LGN) the estimate of total brain (not just the cerebrum cortex) would be different.

Sheth, B. R., & Young, R. (2016). Two visual pathways in primates based on sampling of space: exploitation and exploration of visual information. Frontiers in integrative neuroscience, 10, 37.
Van Essen, D. C. (2003). Organization of visual areas in macaque and human cerebral cortex. The visual neurosciences, 1, 507-521.


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