Two halves, but still whole

NDE researcher Titus Rivas posted a link 0n Facebook to an interesting article called "Split Brain Does Not Lead to Split Consciousness."

One of the most popular arguments against the so-called transmission theory (the idea that the brain serves as a receiver, rather than an originator, of consciousness) involves studies of patients who've undergone a callosotomy — the severing of the corpus callosum, the bundle of nerve fiber joining the left and right hemispheres of the brain. This increasingly rare operation is used as a last resort in cases of severe epilepsy. It has the effect of almost entirely isolating the two halves of the brain, which remain joined only by a few thin threads of nerve tissue (primarily the fornix and the anterior and posterior commissures) which transmit very limited electrical signals.

Previously, scientists who studied the post-op patients concluded that these people now had two distinct centers of consciousness. In effect, where there had been one mind, there were now two. This was taken by many champions of materialism as strong evidence that the mind is generated by the brain, and that mind-body (or soul-body) dualism is untenable.

The new study, however, reaches a different conclusion. Here's a summary provided by the linked article:

A new research study contradicts the established view that so-called split-brain patients have a split consciousness. Instead, the researchers behind the study, led by UvA psychologist Yair Pinto, have found strong evidence showing that despite being characterised by little to no communication between the right and left brain hemispheres, split brain does not cause two independent conscious perceivers in one brain. Their results are published in the latest edition of the journal Brain.

Pinto, lead researcher on the University of Amsterdam team, writes, "The established view of split-brain patients implies that physical connections transmitting massive amounts of information are indispensable for unified consciousness, i.e. one conscious agent in one brain. Our findings, however, reveal that although the two hemispheres are completely insulated from each other, the brain as a whole is still able to produce only one conscious agent. This directly contradicts current orthodoxy and highlights the complexity of unified consciousness."

Though the article says nothing about the philosophical implications of the study, it appears to me that one of the most commonly employed arguments against the brain as a mediator, not producer, of consciousness may now be obsolete. In fact, we can go further and say that the new study's findings are more consistent with transmission than with production. If the mind remains unified even when the brain has been divided, it would suggest that the mind is primary, the brain secondary — that consciousness originates outside the brain and is merely processed by it or funneled through it.

At the very least, the new findings greatly complicate the case for materialism.

Comments

[Vitor]

Here is the translation of what a Brazilian neurocientist said about the article:

About the article, the interesting point here is that it runs counter to the classic experiment of Michael Gazzaniga (Harvard) with "Split Brains". According to the "tradition," individuals with complete corpus callosum lesion (i.e., with almost total rupture of interhemispheric communication) would also exhibit a rupture of consciousness.

Let me give you an example:

Take for granted the idea that the language is interpreted in the left temporal lobe and that the images are perceived in the occipital lobes contralateral to the visual hemifield in which the image is presented. Now imagine that someone is sitting in front of a TV, looking directly at it. A word that appears only in the left half of the screen can be read because the right occipital lobe is able to send the visual image to the left temporal lobe (via corpus callosum) and in this the image of the letters is decoded into a meaningful word. In this same model, a patient who underwent a calosotomy would be unable to read the word, since communication of the right occipital lobe with the left temporal lobe would be impossible. Going a little further, we would be facing an illiterate individual for everything that is written on the left half of the screen and fully able to read the words written on the right half of the screen.

What this article demonstrates (and what strongly needs replication) is that images presented to one cerebral hemisphere can be accessed by the cognitive circuitry of the other hemisphere, even with the sectioned corpus callosum, and this is contrary to the foundations of cognitive neuroscience.

Here we have some possibilities:
 1) these results are wrong and will not be replicated;
2) these results will be replicated but still with the possibility that committees (communications) of small size have (or assume) a more relevant role in inter-hemispheric communication than was previously known; or
3) we are faced with the greatest evidence of non-locality of consciousness already demonstrated.

[Julio Siqueira]

Just as a note: I decided to take a full look (whatever this might mean...) at this work, so I will be taking a lot more time to comment on it. When I do, I will post it on my website, and I will let Michael Prescott know of it.

Very Best Wishes to all,
Julio