I was able to find this MIT technology review[1] that explains that one measure of a specific lexical task gives a processing rate of 60 bits per second. However, the author of the scientific paper in question complains about this summary:
> "I have a small scientific comment on your post. Although I think it represents my results very well, I find the opening sentence: “A new way to analyze human reaction times shows that the brain processes data no faster than 60 bits per second.” a bit misleading. I don’t think I have shown anything about the upper bounds of the processing speed, in principle the curve I show in Figure 4 of the
manuscript could extend far beyond this, but I have no information to make this extrapolation, so I would not claim (for the moment) any upper limit."
Britannica[2] has an explanation of historical estimates, which are in the same ballpark: "For example, a typical reading rate of 300 words per minute works out to about 5 words per second. Assuming an average of 5 characters per word and roughly 2 bits per character yields the aforementioned rate of 50 bits per second." However, 2 bits per character is a 4-letter alphabet, so already they have to be talking about some information theory version where the information density in an English word is much lower than what individual letters can encode (which makes sense, the bigram qz has zero occurences while th is frequent).
It goes on to explain that "in other words, the human body sends 11 million bits per second to the brain for processing, yet the conscious mind seems to be able to process only 50 bits per second" except that his is ludicrous on its face, at least by some measures, as the bps from the eyes alone in the table just below this paragraph is 10 million bps. Clearly, the "lexical task" of reading words involves processing much of that visual input -- even 0.1% would still be 10 kbps -- which is handwaved away in the lexical stream example to pretend that the brain receives a direct serial input stream of 2-bit characters.
Furthermore, it's easy to find other estimates of information processing that suggests the input from a single eye is more like 1.6 gigabits per second[3], which is 320x higher than the 10 megabit total given by britannica. The article explains that there's already compression before it hits the brain, though, as the optical nerve is limited to around 100 megabits per second.
The 120 bit upper limit seems to be an invention of psychologist Mihály Csíkszentmihályi (and purportedly independently by Bell Labs engineer Robert Lucky, though I can find no primary source that supports that claim), and is mentioned in that context in the wikipedia article for Flow[4].
> "I have a small scientific comment on your post. Although I think it represents my results very well, I find the opening sentence: “A new way to analyze human reaction times shows that the brain processes data no faster than 60 bits per second.” a bit misleading. I don’t think I have shown anything about the upper bounds of the processing speed, in principle the curve I show in Figure 4 of the manuscript could extend far beyond this, but I have no information to make this extrapolation, so I would not claim (for the moment) any upper limit."
Britannica[2] has an explanation of historical estimates, which are in the same ballpark: "For example, a typical reading rate of 300 words per minute works out to about 5 words per second. Assuming an average of 5 characters per word and roughly 2 bits per character yields the aforementioned rate of 50 bits per second." However, 2 bits per character is a 4-letter alphabet, so already they have to be talking about some information theory version where the information density in an English word is much lower than what individual letters can encode (which makes sense, the bigram qz has zero occurences while th is frequent).
It goes on to explain that "in other words, the human body sends 11 million bits per second to the brain for processing, yet the conscious mind seems to be able to process only 50 bits per second" except that his is ludicrous on its face, at least by some measures, as the bps from the eyes alone in the table just below this paragraph is 10 million bps. Clearly, the "lexical task" of reading words involves processing much of that visual input -- even 0.1% would still be 10 kbps -- which is handwaved away in the lexical stream example to pretend that the brain receives a direct serial input stream of 2-bit characters.
Furthermore, it's easy to find other estimates of information processing that suggests the input from a single eye is more like 1.6 gigabits per second[3], which is 320x higher than the 10 megabit total given by britannica. The article explains that there's already compression before it hits the brain, though, as the optical nerve is limited to around 100 megabits per second.
The 120 bit upper limit seems to be an invention of psychologist Mihály Csíkszentmihályi (and purportedly independently by Bell Labs engineer Robert Lucky, though I can find no primary source that supports that claim), and is mentioned in that context in the wikipedia article for Flow[4].
1: https://www.technologyreview.com/2009/08/25/210267/new-measu...
2: https://www.britannica.com/science/information-theory/Physio...
3: https://www.discovermagazine.com/mind/the-information-enteri...
4: https://en.wikipedia.org/wiki/Flow_(psychology)#Mechanism