There's a very interesting split-brain experiment [1] and Joe Scott's video about it [2]

TL;DW: Doctors treated corpus callosotomy by severing the bundle of nerve fibers that connect hemispheres of the brain. The surgery effectively stopped seizures from spreading. Left hemisphere handles language, speech, and logical interpretation, right hemisphere handles visual, spatial, and literal tasks.

Because human eyes send visual information to opposite sides of the brain, researchers could show images only to the non-speaking right brain. The right brain could see and physically react to the image (like picking up a matching object with the left hand), but the patient couldn't verbally explain what they were seeing because the left brain was literally in the dark. Instead of saying "I don't know," the speaking left brain would instantly and confidently invent a logical—but completely fake—justification for the action.

[1]: https://en.wikipedia.org/wiki/Split-brain [2]: https://www.youtube.com/watch?v=_TYuTid9a6k