Does brain activity cause consciousness? A TMS experiment

Every morning, you wake up, and a world comes into being for you: sights, sounds, feelings of hunger, thoughts about the work you need to do today. Most of the experiences you have, and most of the things you do in the world, ultimately depend on neurons in your brain sending messages to each other, messages that neuroscientists call “spikes”. But while your brain contains around 86 billion neurons, only a small fraction of them are actually sending spikes at any given moment. So what are the rest of the neurons doing? You may even wonder: if all of the neurons in your brain could be spiking at the same time, could you be hearing more sounds, thinking more thoughts, or getting more work done?

Unfortunately, when too many neurons in your brain spike at the same time, this can lead to a seizure, where you can lose control of your body, and even lose consciousness entirely, as if you are falling into a deep sleep. Your brain works best in a finely-tuned balance, like the way that musicians need to cooperate in an orchestra, or how riding a bicycle takes careful control. But what is it about a balance of neural spikes that makes experience possible in the first place? Why do we have so many thoughts and feelings when we’re awake, but not when we’re in a deep sleep, or when we’ve been given anesthesia for surgery? Does this balance create consciousness for all living things, or even for non-living things like artificial intelligences?

The goal of this project is to study whether the neurons in your brain need to be spiking for you to be conscious. While it may seem like scientists already know the answer to this question, it’s not totally clear. And answering this question has major public health consequences for administering anesthesia, treating people with brain injuries, and understanding what happens in the brain during near-death experiences. In fact, studies of people suffering from heart attacks and of people in deep meditation suggest that it’s possible to have rich experiences when brain activity is almost completely silent, or at least significantly reduced. If this is possible, it would mean that even non-spiking, inactive neurons play a role in one of the universe’s biggest mysteries: creating who you are.

Funding:

• Initiative: BrainStorm Neuroscience Pitch Competition Semi-finalist
• Organization: Mind Science