Theories about the origin of consciousness—the phenomenon that gives humans a way to communicate with each other—have been around for centuries.
But recently, they’ve been bolstered by new evidence that can shed light on the origin and evolution of consciousness.
Theories of consciousness have been developed over the centuries in order to understand how organisms work and how their minds function.
Some of the theories explain how consciousness arises, while others explain how it develops.
But now, a team of researchers has developed a model that explains how the brain works, which can help scientists develop new ways of thinking about the brain and consciousness.
“What we found is that this model is able to explain all the possible pathways of the brain,” explains lead author Daniel Linder, a postdoctoral fellow in MIT’s Department of Electrical Engineering and Computer Science.
“There’s no other model that does that.
That’s the real surprise.”
In order to explain how the human brain works and what it can do, Linder and his team created a model of how neurons in the human hippocampus and cortex work.
The hippocampus is a region of the cerebral cortex where the connections between neurons are active and which is thought to play a role in forming memories.
Linder’s team used computer simulations of the structure of the human hippocampi and cortex to test their model.
“We created a simulation of the entire brain to test our hypothesis that neurons are actually connected and they act as a network,” says Linder.
The simulations revealed that neurons in this region of a neuron’s circuit don’t act independently.
Instead, they are connected together in the same way that they are in the rest of the cortex.
This means that there are a lot of connections in the neurons and they don’t need to be isolated from each other.
This, in turn, explains how we can talk to our neurons.
In other words, it explains how communication with other neurons is possible.
“The fact that we can get this same behavior in a network with neurons that are not connected to each other, and so you can actually have this communication without a connection,” explains Linder of the results.
The researchers then compared this model to another model, one which proposes that the human mind is made up of billions of neurons, each with its own memory.
The model suggests that each neuron acts independently of the other, creating a complex pattern of connections.
“That was the biggest surprise,” says study coauthor Peter Fischler, an assistant professor in MIT College of Engineering.
“It’s actually an explanation of the way the human consciousness is generated.”
“This is a very interesting and challenging problem,” says Fischling.
“To have a model to explain these kinds of processes—the way the brain actually works—is an exciting thing to be able to apply to new problems.”
The researchers also discovered that the brain’s cortex can be thought of as a series of connections, or layers, connecting neurons in different parts of the circuit.
This process allows the brain to create a complex network of connections between different parts and to be in control of this network.
This is a critical insight, says Linders, because the neural circuitry of the neocortex is very complicated, with hundreds of thousands of neurons.
“Our model has a number of insights that are very important for understanding how the neocortical circuitry works,” says Dr. Daniel Bowers, an electrical engineering professor at Harvard Medical School who was not involved in the research.
“If you understand how the neural network works, then you can understand the network of neurons.”
Linder says that he and his colleagues are already looking for ways to extend this model further, to explain more complex neural networks that can also act independently of each other in complex ways.
“These new results have really opened the door to new questions, and we’re just starting to explore that,” he says.
“But this is a great result that will help us understand how consciousness and the brain work.”
The model also has some major drawbacks.
“I’m still not convinced that it’s a good model of consciousness,” says coauthor Daniel J. Gollwitzer, a professor of physics and astronomy at the University of California, Santa Barbara.
“My initial feeling is that it doesn’t capture everything about how the cortex works.”
But Linder believes that the model could provide important insights into how consciousness is created.
“Because the model is so simple, it has a very simple explanation of how it all works,” he explains.
“You don’t have to think in terms of abstractions, like you might think of an image or a string of numbers or a picture.
You just have to know about how these are connected.”
The team’s results will be published in the journal Nature Neuroscience.
This work was supported by grants from the National Institutes of Health, the National Science Foundation, and the National Institute of Neurological Disorders and Stroke.