4 hours ago
https://picower.mit.edu/news/cognition-a...new-theory
EXCERPTS: A new theory, published in The Journal of Neuroscience by three scientists in The Picower Institute for Learning and Memory at MIT, offers an explanation of how the brain produces cognition and consciousness: It uses traveling waves of rhythmic neural activity to coordinate nimble neural networks with analog computations.
The metaphor that the brain operates with “circuits” is incomplete, said Picower Professor Earl K. Miller, the paper’s senior author. Indubitably, the brain’s physically connected circuits provide the infrastructure to store our memories and represent our ongoing needs and goals. But when we need to make improvised use of that knowledge in the rapid-fire, anything goes sensory context the world constantly throws our way, we can’t just depend on the relatively slow chemical process of rewiring those circuit connections called “synapses,” he said. Instead, the brain needs a control system that can coordinate millions of neurons to process information in a fraction of a second. Brain waves, long understood to be the synchronized rhythmic fluctuations of large groups of neurons, turn out to be performing that crucial service, Miller and his colleagues argue, citing years of experimental evidence from his lab and many others.
“Circuits and synapses are important and fundamental, that’s the start. But there is more going on,” said Miller, a member of MIT’s Brain and Cognitive Sciences faculty. “The brain generates waves, and wave dynamics are a highly efficient way to coordinate and perform computation”
While digital circuits make calculations one step at a time through sequential switches and gates, analog computation, which can be performed via the interference of waves, processes multiple calculations in parallel. That’s not only more efficient, but also locally focused traveling waves happen to be a ubiquitous feature of the brain, the scientists note.
“The brain exploits its own physics,” wrote Miller and co-authors Scott L. Brincat and Jefferson E. Roy, who are research scientists in Miller’s lab.
The new theory is important not only because it provides an explanation of cognition and consciousness, but also because it asserts the potential importance of considering waves in clinical treatment. Conveniently, waves can be manipulated non-invasively.
“Developing treatments based on brain wave dynamics is not just an opportunity but also an obligation,” said Miller, whose lab is part of a collaboration studying brain waves in autism.
[...] The article asserts that consciousness “emerges when these dynamic wave patterns bring the cortex in an organized, globally integrated state, one that naturally links and influences widespread activity.”
Some of the most compelling evidence linking wave dynamics to consciousness, comes from studies of general anesthesia that Miller has conducted with Picower Institute colleague Emery N. Brown, who is an Institute Professor at MIT, an anesthesiologist at Massachusetts General Hospital and a Professor in Harvard Medical School. Their labs have shown that three different drugs, each with different molecular mechanisms of action, all similarly disrupt brain wave dynamics to produce unconsciousness.
“Consciousness depends less on specific receptors or cell types and more on the integrity of large-scale wave organization,” the authors write in the review.
In other words, much like cognition, consciousness depends on how the brain efficiently organizes itself with brain waves... (MORE - missing details)
EXCERPTS: A new theory, published in The Journal of Neuroscience by three scientists in The Picower Institute for Learning and Memory at MIT, offers an explanation of how the brain produces cognition and consciousness: It uses traveling waves of rhythmic neural activity to coordinate nimble neural networks with analog computations.
The metaphor that the brain operates with “circuits” is incomplete, said Picower Professor Earl K. Miller, the paper’s senior author. Indubitably, the brain’s physically connected circuits provide the infrastructure to store our memories and represent our ongoing needs and goals. But when we need to make improvised use of that knowledge in the rapid-fire, anything goes sensory context the world constantly throws our way, we can’t just depend on the relatively slow chemical process of rewiring those circuit connections called “synapses,” he said. Instead, the brain needs a control system that can coordinate millions of neurons to process information in a fraction of a second. Brain waves, long understood to be the synchronized rhythmic fluctuations of large groups of neurons, turn out to be performing that crucial service, Miller and his colleagues argue, citing years of experimental evidence from his lab and many others.
“Circuits and synapses are important and fundamental, that’s the start. But there is more going on,” said Miller, a member of MIT’s Brain and Cognitive Sciences faculty. “The brain generates waves, and wave dynamics are a highly efficient way to coordinate and perform computation”
While digital circuits make calculations one step at a time through sequential switches and gates, analog computation, which can be performed via the interference of waves, processes multiple calculations in parallel. That’s not only more efficient, but also locally focused traveling waves happen to be a ubiquitous feature of the brain, the scientists note.
“The brain exploits its own physics,” wrote Miller and co-authors Scott L. Brincat and Jefferson E. Roy, who are research scientists in Miller’s lab.
The new theory is important not only because it provides an explanation of cognition and consciousness, but also because it asserts the potential importance of considering waves in clinical treatment. Conveniently, waves can be manipulated non-invasively.
“Developing treatments based on brain wave dynamics is not just an opportunity but also an obligation,” said Miller, whose lab is part of a collaboration studying brain waves in autism.
[...] The article asserts that consciousness “emerges when these dynamic wave patterns bring the cortex in an organized, globally integrated state, one that naturally links and influences widespread activity.”
Some of the most compelling evidence linking wave dynamics to consciousness, comes from studies of general anesthesia that Miller has conducted with Picower Institute colleague Emery N. Brown, who is an Institute Professor at MIT, an anesthesiologist at Massachusetts General Hospital and a Professor in Harvard Medical School. Their labs have shown that three different drugs, each with different molecular mechanisms of action, all similarly disrupt brain wave dynamics to produce unconsciousness.
“Consciousness depends less on specific receptors or cell types and more on the integrity of large-scale wave organization,” the authors write in the review.
In other words, much like cognition, consciousness depends on how the brain efficiently organizes itself with brain waves... (MORE - missing details)
