Unexplained communication between brain hemispheres without corpus callosum
October 21, 2011
Magnetic resonance images comparing a healthy subject (left) with an AgCC patient (right). The corpus callosum is the thick, c-shaped structure outlined in the healthy brain and missing from the AgCC brain. Bottom image: Functional magnetic resonance images highlight symmetric patterns of synchronized activity in both healthy (left) and AgCC subjects (right) during rest with eyes closed. More than 15 of this type of network were found to be preserved in AgCC subjects. (Credit: California Institute of Technology)
Could the brain be using electromagnetic fields to communicate between hemispheres — the electromagnetic field theory of consciousness proposed by Johnjoe McFadden (School of Biomedical and Life Sciences, University of Surrey)?
Neuroscientists at the California Institute of Technology (Caltech) have made a puzzling finding: people born without a corpus callosum (which links the two hemispheres of the brain) — a condition called agenesis of the corpus callosum, or AgCC — still show remarkably normal communication across the gap between the two halves of their brains.
According to J. Michael Tyszka, associate director of the Caltech Brain Imaging Center, many areas of the brain display slowly varying patterns of activity that are similar to one another. The fact that these areas are synchronized has led many scientists to presume that they are all part of an interconnected network called a resting-state network.
Neuroscientists baffled
Much to their surprise, Tyszka and his team found that these resting-state networks look essentially normal in people with AgCC, despite the lack of connectivity.
“This was a real surprise,” says Tyszka. “We expected to see a lot less coupling between the left and right brain in this group — after all, they are missing about 200 million connections that would normally be there. How do they manage to have normal communication between the left and right sides of the brain without the corpus callosum?”
AgCC occurs in approximately one of every 4000 live births. The typical corpus callosum comprises almost 200 million axons — the connections between brain cells — and is the largest fiber bundle in the human brain. In AgCC, those fibers fail to cross the gap between the hemispheres during fetal development, forcing the two halves of the brain to communicate using more indirect — and currently unknown — means.
According to the team, the findings are especially valuable in light of current theories that link impaired brain connections with clinical conditions including autism and schizophrenia.
“We are now examining AgCC subjects who are also on the autism spectrum, in order to gain insights about the role of brain connectivity in autism, as well as in healthy social interactions,” says Tyszka. “About a third of people with AgCC also have autism, and altered connectivity in the corpus callosum has been found in autism. The remarkable compensation in brain functional networks that we found here may thus have important implications also for understanding the function of the brains of people with autism.”
Ref.: J. Michael Tyszka, et al., Intact Bilateral Resting-State Networks in the Absence of the Corpus Callosum, The Journal of Neuroscience, 2011; [DOI:10.1523/JNEUROSCI.1453-11.2011]
Comments (15)
by Jolene
Well when you guys figure out HOW our brains communicate.. plz let This ACCer know.. my two body halves still fight each other :( Example one foot wanting to move while my other goes the oposite way.
by Hamertime
This is similar to the question of how any synchrony (particularly high frequency gamma) is mediated between hemispheres: corpus callosum, thalamus, brain stem, e-m field, and/or quantum. I think quantum processes accompany electrophysiology, but both need some anatomical connection.
There are also still anatomical connections between hemispheres without corpus callosun, e.g. brainstem and thalamus. We know gap junctions between neurons (and glia) in thalamus link the hemispheres (Traub), mediate gamma synchrony and consciousness.I guess this also means IBMs brain mapping (based on corpus callosum) is in trouble.
by AeaeaActual
This fits well and truly within the “extraordinary claims require extraordinary proof” category. Don’t leap to conclusions. While EMF theory has a chance of being correct, it’s unlikely. It’s far more likely that, like the brains of birds, these individuals’ brains develop bilateral reactions to similar stimuli over the course of a lifetime. (Make no mistake that this test’s so-called lack of stimulation is not to be interpreted as such—the brain is always stimulated.)
Bilateral development requires no new, radical theories of the brain. EMF theory certainly does, and EMF theory fails to explain many other neurological phenomena, so it is not likely correct. To leap to quantum theory is defensible neither with currently understood theories of the brain, nor is quantum theory required to discuss even EMF theory—that’s just an irresponsible leap, in the context of these data.
In other words, get a grip.
by Guido Brandt Corstius
Maybe for something different this link : http://www.linkedin.com/groups/brain-you-two-2316564.S.72891581?qid=ffee658f-eadc-44f0-81a0-5148c3c6a22e&trk=group_most_popular-0-b-ttl&goback=%2Egmp_2316564
An amateur discussion about the brain.
by Darth Continent
Will a market emerge for Magneto-style helmets to prevent electromagnetic radiation from influencing our thoughts?
by joeThorpe
If they are both copies of the same code, receiving the exact same input, at the same time and rate, it would be strange if they where wildly different.
I wonder if they have tested left ear/eye watching horror while right ear/eye watches peaceful nature. I would see if I could get them to run different before I would start down crazy lanes of thought (quantum brain).
DNA already builds and runs a machine trillions of times larger then itself. It does not need to be building a quantum computer to be a worthy of praise.
by Malix
30 seconds of Google tells me that this partial synchronization between hemispheres is caused by AgCC brains still having an anterior commissure, a separate, smaller connection between brain hemispheres.
From http://www.travisinstitute.org/acc/
“Individuals with ACC have normal interhemispheric color-word (Stroop) interference. That is, when a patch of color to be named is presented in one visual field there is a slower and less accurate response if a different (interfering) color word is presented simultaneously in the other visual field. This result suggests that despite callosal absence, there is still some remaining interhemispheric transfer of information. The anterior commissure (a very much smaller interhemispheric pathway present in the majority of individuals with ACC) is the most likely route for residual interhemispheric transfer in ACC.”
Also see:
http://en.wikipedia.org/wiki/Anterior_commissure
I’m guessing that since the AgCC brains never had a corpus callosum when they were developing, it just adapted by using the anterior commissure as best it could. At least, this is a whole lot better guess than neurons using nonexistent wifi structures to communicate and having physical wiring for no apparent reason.
by Malix
Also, this thread has neuroscientists discussing this question with much better knowledge than just my random Googling:
http://www.reddit.com/r/askscience/comments/ljzzb/does_the_unexplained_communication_between_brain/
by Hminus
Who knows? It seems unlikely by what we know, but nature’s ingenuity knows no bound.
If the answer is yes there are gonna be a lot of experts trying to take back everything they have said about quantum models of the brain.
As I said before though, I suspect the solution will be something far less surprising… let’s hope I’m wrong.
by Porkov
Quantum entanglement?
by Hminus
This could be gorundbreaking, but I suspect a simpler explanation will be found.
Also, Hooray for McFadden. I’ve always found his theory interesting, I wonder how Persinger and Bernard Baars will react to this possible confirmation of it.
by melajara
Actually, most of the synchronization of the hemispheres is performed through long range electron quantum tunneling ;-)
by gawells
It seems some brains might have Wi-Fi.
They say great minds think alike, can’t be too surprising when two hemispheres have the same thoughts, or dissimilar ones when connections either fail or never get established, as well as intermittent varieties betwixt and between.
by Ralph Dratman
Two halves of a brain communicating with WiFi? What an absurd theory.
Obviously it’s Bluetooth.
by eldras
uh-oh—
If this is true we have a new set of axioms in human intelligence.