Quick: How many thoughts do you think you have per day? One thousand? A million? According to researchers at Queen’s University in Canada, the average person has about 6,200 thoughts a day. To calculate this, they’ve developed a new way to measure what they call thought worms: the point at which one thought ends and another begins.
As brain imaging techniques have improved over the years, neuroscientists have been working to decode what our brains are thinking about by simply observing the electrical activity taking place inside them. For example, researchers have been able to look at the brain’s activity and figure out that a person is thinking of a particular object like a house or a face. To accomplish this, they draw up templates of thought patterns related to observations. The problem with this, though, is that for a comprehensive picture of what the brain is thinking at any one time, you need thousands of templates.
So the Queen’s University team decided to abandon the goal of decoding what individual thoughts were about, and instead focused on simply figuring out when one thought ends and another begins.
According to Jordan Poppenk, the Canada Research Chair in Cognitive Neuroscience:
“We had our breakthrough by giving up on trying to understand what a person is thinking about, and instead focusing on when they have moved on. Our methods help us detect when a person is thinking something new, without regard to what the new thought is. You could say that we’ve skipped over vocabulary to understand the punctuation of the language of the mind.”
To achieve their goal, the researchers turned to the field of neurocinematics, the science of how watching movies affects our brains. By showing participants movies and monitoring their thoughts using a functional MRI, the researchers were able to see when one thought ended and another began by mapping the electrical activity of the brain to new events on the screen. Neurocinematics was useful here because when watching movies, our thoughts follow in a specific order, rather than when we’re unoccupied, and our thoughts drift from one to the other.
“What we call thought worms are adjacent points in a simplified representation of activity patterns in the brain,” explained Poppenk. “The brain occupies a different point in this ‘state space’ at every moment. When a person moves onto a new thought, they create a new thought worm that we can detect with our methods. We also noticed that thought worms emerge right as new events do when people are watching movies. Drilling into this helped us validate the idea that the appearance of a new thought worm corresponds to a thought transition.”
The researcher team, which includes Poppenk’s graduate student, Julie Tseng, is confident that their work can give us much greater insight into how the brain functions and possibly even help us learn how chemicals like caffeine in coffee could change the rate of our thoughts and how aging and certain disorders affect the mind.
“For example, how does mentation rate—the rate at which thought transitions occur—relate to a person’s ability to pay attention for a long period?” said Poppenk. “Also, can measures of thought dynamics serve a clinical function? For example, our methods could support early detection of disordered thought in schizophrenia, or rapid thought in ADHD or mania. We think the methods offer a lot of potential; we hope to make heavy use of them in our upcoming work.”
The team’s research has been published in the journal Nature Communications.