Interesting, I experimented a bit with this when my daughter was younger. I used to walk around the room with her in my arms singing to get her to sleep. To ensure she would be settled I would then count 300 steps before putting her in the cot. I discovered I could count and sing at the same time by visualising the number in my head, instead of using my inner monologue. But it requires more focus to maintain.

Thankfully these days she can get herself to sleep. But I miss it sometimes

I've noticed something similar. I can listen to audiobooks and follow/absorb what is going on without really paying attention, as long as I am not trying to read something. I can't follow an audiobook and read at the same time. This is probably because I subvocalize when I read. I have taken speed reading courses but I don't enjoy reading that way. I like feeling every word as I read.

This has everything to do with the fact we have two brains. The left and right brain (more specifically the left and right hemispheres of the Cerebral Cortex) hold different functions cognitively, control the motor movements of the opposite sides of the body, and communicate thru the Corpus Callosum. Your full consciousness, or thought, is almost like a 'stream' created at this meeting point of the two brains where the neural traffic is so dense (more like my own theory...). However, if you were to find a patient where this connection is severed, like an epileptic patient whos Corpus Callosum was surgically bisected to cure them of chronic seizures, you would then have someone with 2 separate brains that cant talk to one another. This is split brain theory. I wrote a paper on this in undergraduate and id have to pull up a ton of other details, but essentially go watch videos on Michael Gazzaniga and Dr. Roger Sperry's experiments with these people. They would experience the right brain reaching for one outfit to get dressed in the morning while the left brain "thought" the idea of another outfit, so they would be very confused. Its very revealing to the mapping of our brain and all the different human functions, and how we learn! Then you lead down the rabbit hole of Bicameral Mind... but anyways, i believe thats why everyone can count in their left brain, and then from there its up to each brain system to figure out how to map the second task to the right brain so they can enter the consciousness stream simultaneously. There is an internal mechanism everyone develops themselves and Feynman is showing you can test that. Its probably right around most humans cognitive limit to use the right brain to help either reading OR speaking as the left brain is the primary handler of all of these (math, reading, speech). I also think thats why Feynman saw colors with his math; his right brain was assigning a unique identifier (color) to his logical problem being worked out in his left brain (all the different symbols and letters). Fascinating.

Interesting, I often sing a good night lullaby to my kid and have discovered it’s trivial to read while doing so. But I just tried talking while counting in my head and it felt like a brick wall was blocking me.

How do we know, or would Feynman know, that they can count while reading and not just that counting and reading are simple enough tasks broken down into discrete steps that our brains can context swap in an unnoticeably short unit of time?

Just trying to read your post while counting at a consistent pace I associate with roughly 1 second per number, it didn't feel like I was reading words but instead scanning them and understanding them after the fact from memory. Usually when i read I hear the words 'in my head' but not while counting at the same time.

i wish i could do syntax highlighting in my head

I can also count while reading, I just tried it. But I can't write while counting.

I can have one interpretation and one generative task running at the same time.

Honestly my takeaway from this is that simple experiments like this are very important in identifying how brains work. I am admittedly a fanboy of Feynman, but I believe these kinds of questions are worth a dozen EEGs or fMRIs asserting how the brain works.

I wonder how musical counts interact with this.

This is a nice example of using interference as a window into representation

> while Feynman imagined himself talking to himself

ironic )

Try counting by imagining fingers in your head and talking at the same time. (-;