Debate: 'Do Split-Brain Patients Have Two Minds?' (LeDoux, Pinto, Schechter)

Debate between Joseph LeDoux, Yaïr Pinto and Elizabeth Schechter at NYU on September 18, 2018. Moderated by David Chalmers. Sponsored by the NYU Center for Mind, Brain and Consciousness.

[EnejJohhem]

Fact that Pinto actually conducted a split brain experiment, and found that a person with split brain still have one consciousness is a shocking observation.

[johnb]

I can't help but wonder how our interpretations of the data and the concepts being influenced by this concept that there is a single "you" inside. If both brains are distinct and individual, they are still both the same person. Like a clone or a twin that simply sees the world and experiences it and processes it in a slightly different way than the other side of the brain. I think our own singular experience, this seemingly unified feeling that our brain convinces us we have prevents us from really comprehending how this really works. Like the phrase stated, "it's complicated".

Also, another point to note. At no point in the life of a human would each half of the brain ever expected to actually experience and process individually without the other half. So why would we suddenly expect each half of the brain to identify as individual halves when it spent the whole life working as a singular unit? Our brains would have had to evolve to work in concert, and so even after severing the corpus collosum, each half would still think of itself as the "you".

[Dade-xoxt]

Basically, this all boils down to whether the brain is the generator of consciousness or simply a receiver.

[belliotrungy]

You can speed Chalmers up and he still sounds normal

[XMIRC]

To robotaholic: That's why we need to perform the scientific medical experiments to settle this once and for all. It will likely settle all philosophical and spiritual questions about consciousness/the soul/mind/philosophical zombies, etc. and we won't have to debate this on Youtube You saw my methodologies below. The scenarios involve the PHYSICAL splitting of a brain into 2 seperate physical bodies and the various permutations of that, including swapping hemispheres between 2 bodies.

[XMIRC]

There is another possible factor here, merely splitting someones brain inside their own body is insufficient. A TOTAL physical break needs to be done - a BREAK from the body. We already know that even if the corpus is severed, there are indirect pathways via other structures that could allow the right and left hemisphere to co-operate. For example, if my right brain sends a signal to another body part, that body part may have a neurologival pathway to my left hemisphere. The two hemispheres are not 100% isolated in that respect. The only way to eliminate this variable is COMPLETE dissociation from the physical body.

[XMIRC]

If this could be done (ethical issues understood). ALL questions would be answered I think - psychologically, philosophically, and even for physics.

[edit_duplicate]

A really interesting discussion overall. I was particularly impressed with Schechter’s presence; it’s apparent that she has a substantial grasp on the literature, which she utilized cogently and concisely in this discussion. I went down a bit of a rabbit hole to find this video, but I’m glad I did!

[XMIRC]

Experiment #2: One doner subject and 2 recipients. Both hemispheres of a doner are transplanted into 2 seperate recipients (brain removed)

[amitashi]

Thing that should be mentioned about these experiments is they deal with MEMORY, because words just blink in ths screen and THEN person should answer what he SAW. It seems hemispheres can't transfer memories to each other and operate each other's memories. But it doesn't mean person wasn't aware of these words WHILE they were shown.

[danya]

thank god there is a subtitle, I barely can hear them.

[adriana]

Thank you very much! This was so interesting!!

[Paulus_Brent]

The confusion arises only because we conflate mind with self awareness. I can have conflicting thoughts, even two minds, but being the same subject with a unified sense of selfhood. I think Pinto got it right, there is no compelling evidence for two "persons" in split-brainers.

[sampoornamkannan]

No, they work at different wavelengths at different times.

[squakke]

Which side of this ladies brain decided it was a good idea to chew gum while giving a speech

[XMIRC]

FYI all, I wrote a paper in the 70s about this that was published without giving me credit about the ideas (University of Calgary) - I already posted this here a long time ago. I have had many responses to my scenarios over the last while - I hope I have clarified everything properly. Since then, I have thought about one scenario a lot - the case where two donors swap hemispheres ("You and I together in 2 skulls") and what transpires afterwards. From the "consciousness" perspective, it will open up a whole can of worms, or bring astounding discoveries. it will also kill or create new philosophical aspects. PS - I doubt that the prof that kept my paper will step up and acknowledge me.

[adcaptandumvulgus]

I've often wondered if the right hemisphere has a link to our subconscious and that it basically is the way the right side has a way to communicate, similar to dreaming maybe. As it doesn't have anything to directly communicate, like the left does. I listen to my intuition/hunches and it usually doesn't lead me astray. My experiences, like going with th.e first guess on the test is usually right because I think that's usually Captain subconscious. I suspect but I don't know for sure I'm not omniscient. my two cents. Wherever I am we're never alone. Ooh maybe it actually has schizophrenic ties to it in some way too I don't know That's interesting I didn't think of that Time to dig some more.

[NeoShaman]

From my own experience, I can say that the brain, both hemispheres are a shared resource, which can be used by different entities to a different degree. Usually, that resource is dominated by consciousness, but it can release and observed. This is how two-minds can be observed retrospectively. That example with driving a car and listening to the radio is not sufficient to trigger it, because both are external sources of stimulation. What we need is an extremely strong and long attention hook from the outside. Naturally, after few minutes, the mind will drift to internal chatter. Now if we stay in that dual attention state for long enough, consciousness grip on the body will loosen, and eventually, it will be lost (for some time). Something else will take over the control, and use the body according to its will. Consciousness will be aware of it, but not in charge of what is happening. The first thing that is striking is the change in personality. How things are done, what is spoken and how it's spoken, reactions to situations, everything changes.

[eXWoLL]

Really interesting debate, which makes one wonder..

-If the conscience/control agent/higher cognition is the same, or seems being the same, both by "himself" and the people that knows him or tested him prior and after the surgery, then:
What is the mechanism that generates or "host" "us", if the brain working separately is still able to generate it? Or in the case of the early "split-brain" signs which "heal" with time, which is the mechanism the brain uses to get back to normality?
-If the "person" is the same, however, the decision making process is different based on the separated input, and this person does not notice or feel the contradiction of his actions/thoughts. In other words the control agent being hosted in only one side of the brain (which isnt affected by the split), and the mechanisms which it uses to operate the body being separate in each emisphere.

Then wouldn´t this mean that there aren´t, possibly, 2 entities in one brain (or people), but actually three?

The persons Concience (or thinking/control agent)
The left self, which expresses directly and through the agent
The right self, which expresses directly and through the agent

The later two gaining a leverage on agent use by some chemical/nerunal mechanisms?.

Which wouldn´t present the whole picture as a driver in control of different cars, which operate differently but at the control agents will, but instead as a rider in control of two horses?

Ultimately all of this taking one to the question of: Are we really the individual we think we are? Or "we" are just a CPU unit in our bodies PC, which only automatically processes whatever info is given by both its other hardware and software components?

An experiment of a brain splitting in a multiple personality disorder patient would reveal a lot of interesting data in this sense I believe....

[Jueyes-vggb]

Its two seperate consciousness think about it, they start out identical at the cut, but after that point they experience the world different and from that point they are two separate entities