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Comment by xwdv | Hacker News Reader

Will you get different thoughts and ideas if you read a book with one eye closed vs the other?

I read some brain encyclopedia ages ago, so details are a bit foggy, but when the connections between the two hemispheres of the brain gets injured/damaged it can have some really strange effects. In the book they retold tests where they did things like showing a picture of a shovel to only one eye and ask the person to think of a garden tool, and they'd say shovel. Then they'd ask the person to explain why they're thinking of a shovel, and they'd tell some elaborate story like having met their neighbour a few days ago who said that they need to buy a shovel, or something similar. This due to the connection between the part(s) of the brain that constructs the story having severed connections to the parts the receives and processes the visual input of that eye. There was a few hundred pages of tests like these with wildly different effects depending on where the connections had been damaged.

Without injury the input should be shared just fine, but since the difference is so severe when the connections are damaged I guess (with no credentials or so to back it up) that there could be some hard-to-measure differences in thoughts formed depending on which eye is used.

So it seems the answer would be yes, but we can't say how or to what extent.

A severed corpus callosum - sometimes done to mitigate the effects of sever epilepsy (the seizure on one side of the brain can't travel to the other side).

Scientific American Frontiers : severed corpus callosum https://youtu.be/lfGwsAdS9Dc

An intressting thing with that, is that the side of the brain that controls speech might be completly accurate. It could have said showel cause that side of the brain thoght of its neighbors shovel. The only thing that it would be missing would be that it was influenced to think of that shovel event by input given to the other brain half.

I do.

Try it, YMMV.

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Normally when you look into your own eyes in a mirror they are each looking into themselves.

If you cross your eyes and get the distance just right, you can look into each eye from the other.

For me it causes a strange effect, or seems to. I would be interested to hear reports from others of their subjective experience of doing that?

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Edit to add: Reading aloud also has different effects than reading silently. I surmise that the extra feedback loop from voice to ear has something to do with it.

A common proofreading trick is to read your writing aloud. You catch errors that are [negative hallucination?] elided by, uh, non-external loops.

Your auditory memory is a different space than other forms of memory, so when you read aloud to yourself it permits you to buffer additional information and get to it later, in addition to mapping it through different perceptual space as you’ve noted. So at least the perceptual circuit and the time constraints are changed by doing so.

I find that it no longer works very well for me though: I often read aloud without experiencing or remembering anything I’ve read at all. It’s the same autopilot that takes over driving.

Both may be true!

A life hack I found useful: if I need to remember a few numbers for a few minutes before I can write them down, I keep quietly repeating them in my mind. It works much better for me than trying to memorize them since I think it uses auditory memory; after a few repetitions the sequence of words becomes automatic and easy to repeat without thinking.

"Some of the most famous examples of confabulation come "split-brain" patients, whose left and right brain hemispheres have been surgically disconnected for medical treatment. Neuroscientists have devised clever experiments in which information is provided to the right hemisphere (for instance, pictures of naked people), causing a change in behavior (embarrassed giggling). Split-brain individuals are then asked to explain their behavior verbally, which relies on the left hemisphere. Realizing that their body is laughing, but unaware of the nude images, the left hemisphere will confabulate an excuse for the body's behavior ("I keep laughing because you ask such funny questions, Doc!")." https://www.edge.org/response-detail/11513

It is a fascinating series of experiments.

For others interested, look up Roger Sperry's split-brain experiments[1], done at CalTech. He received the 1981 Nobel Prize for the work. I'm surprised the above article doesn't mention it.

We don't cut cut peoples' brains in half any more, so it was a unique moment in time when they had people available with this condition, and the results are quite illuminating.

Here's a video with some interviews with real patients: https://www.youtube.com/watch?v=aCv4K5aStdU

And a here's a timestamp where one of the experiments is performed: https://www.youtube.com/watch?v=aCv4K5aStdU&t=101s

[1] http://scihi.org/roger-wolcott-sperry-split-brain/

Not in a healthy human.

Cutting (or partially severing) the corpus callosum connecting the hemispheres of the brain has been shown to have some interesting results along those lines, though: https://en.wikipedia.org/wiki/Split-brain

I recall reading that cannabis use was supposed to inhibit this communication between the hemispheres via the corpus callosum.

That is such a wild idea. I wonder if you dance with one eye covered or learn a language solely thru input from right vs. left eye (and ears) would it matter? Or what about musicians like Jimi Hendrix who played their instrument backwards?

It seems un-testable in terms of eliminating any sort of placebo/expectation effect though.

Various corrective surgeries for vision over the years have intentionally mismatched focal distance between eyes. Presumably there are at least tens of thousands of people that can only read up close with one eye, and at a distance with the other.

I personally was born with a crossed eye. It's been corrected, but the reading acuity of my secondary eye is worse than my primary. Everything is in focus optically, but reading is more strenuous. It's almost as if there's some letter or syllable sized gaps my brain is interpolating around. Perhaps I only notice it when reading because of the density of high frequency content in all the letters.

Too slow connection between the secondary eye and letter recognition center?

the contralateral "wiring" is also conserved in the retinal processing.

left field of retina in both eyes communicates contralaterally with right hemispheric optic cortex, vice versa.

I agree, eyes are even more weird. There is a nice image here showing how they are conected https://www.quora.com/Which-side-of-the-brain-does-the-optic...