For most of human history, consciousness has been something that scientists have talked around. It hasn’t really been something they could test. That is, until now. Researchers have begun to treat consciousness as something that they’re able to measure directly using brain signals. It’s all going down at MIT.
A group of neuroscientists & philosophers at MIT has come together to create the MIT Consciousness Club. While these groups usually focus on separate fields, they’re now working alongside one another to solve a shared problem. They’re trying to measure consciousness without relying on behavior or self-reporting. They essentially want to know whether a brain is capable of conscious experience at all, even when a person is unable to speak or move.
The two leaders of the MIT Consciousness Club are Matthias Michel & Earl K. Miller. Michel is a philosopher in the Department of Linguistics & Philosophy at MIT. His work revolves around how science defines and measures things that we can’t directly see.
Miller is a neuroscientist. He is the Picower Professor of Neuroscience, and he has a decades-long history of studying how the brain supports memory & attention. His lab has become quite well-known for its work on the prefrontal cortex & large-scale brain coordination.
Interestingly, “measuring consciousness” isn’t related to measuring emotions or thoughts. It also has nothing to do with personality, either. Scientists are actually measuring levels or states. They’re trying to distinguish between states like being awake or asleep, as well as under anesthesia or in a slightly conscious state. The most important requirement is that the measure works even when the person is unable to follow instructions.
One of the most common tools being used in this field is the Perturbational Complexity Index, also known as PCI. It involves sending a magnetic pulse to the brain cortex, then measuring to see how the brain’s electrical activity spreads & evolves afterward. Once that’s done, they use compression algorithms to analyze the EEG signals. A rich response that’s hard to compress creates a higher PCI score, while simple and short-lived response has a lower score.
However, PCI doesn’t tell you what someone is thinking or even feeling. Rather, it tells you whether the brain is capable of sustaining certain activity patterns after it is stimulated. One paper in Nature Reviews Neurology actually claims that PCI is a tool for understanding the level of consciousness in unresponsive patients. They claim it shouldn’t be seen as a full description of the conscious experience.
Measuring consciousness is quite the challenge, as you might expect. For starters, not everyone agrees on what consciousness actually is, and that affects ideas of measurement. Neuroscientist Giulio Tononi says that consciousness is related to the amount of integrated information that a system generates. He developed a system called Integrated Information Theory (IIT) to model this idea.
Others, like Matthew A. Cerullo, question whether it’s possible to apply IIT’s mathematical definitions to real systems. There are also those who believe in the “global workspace” theory. Supporters of this belief argue that we should focus on information sharing across the brain instead of complexity. Stanislas Dehaene, Michel Kerszberg & Jean-Pierre Changeux describe a kind of brain system where information only becomes conscious after being broadcast across long-range neural networks.
But the goal of the Consciousness Club isn’t to encourage one theory over others. Their goal is more about testing how measuring consciousness should work at all. For example, Michel has questioned the timing of consciousness and how long it takes for a stimulus to enter conscious awareness. He has raised concerns over how we should interpret neural activity & experience.
The Club is also looking into things such as unconscious perception and animal consciousness, alongside artificial systems. It appears that they want to apply these measurement tools beyond healthy adult humans so that we can have a better understanding of consciousness.
The biggest questions about this research center around using machines. If a machine is able to tell whether or not a brain is conscious without asking a single question, then what should count more? Is it the number the machine produces or the theory behind it? Perhaps it’s the way it’s used that’s important.
Either way, it remains an open question. It’s exactly the sort of thing that researchers at MIT are trying to solve. They’re working their way through, one experiment & one argument at a time.
