What Do People Who Are Conscious But Lack a Cortex Demonstrate?
Hydranencephaly means that the two brain spheres are largely absent. It is not to be confused with hydrocephalus, which just means water on the brain. Recently, neurosurgeon Michael Egnor and I have been looking at the claims made in an article in Popular Mechanics in connection with our book, The Immortal Mind: (2025). The many misconceptions the PM article introduced have provided us with an opportunity to discuss some topics at greater length than we could do in the book. One of these topics is people who are born without a cortex. From the PM article: He also talks about near-death experiences, current theories of consciousness, and the concept of hydranencephaly, a rare condition where a patient is missing large parts of their cerebral cortex. That this condition exists disproves all current theories of consciousness, says Egnor in our interview, because they all maintain it originates in the cortex. There have only been a few documented cases of hydranencephaly in the literature. Steven Novella, a Yale School of Medicine neuroscientist, and Newsome both stressed that …


