Transitions Of States Of Brain Activity Were Associated With The Appearance Of New Thoughts
Canadian neuroscientists have tracked the transitions of brain States to fMRI and linked them to the emergence of new thoughts. When watching the movie, the transitions coincided with the change of scenes, and in neurotic people, the transitions were more frequent. The authors of the paper, published in the journal Nature Communications, note that their approach allows us to study thinking at rest without prior preparation, but may require additional tests.
Previously, the only way to know a person's mind was introspection or self-observation. Now cognitive science has mastered new methods and advanced in understanding the structure of consciousness. In particular, scientists even managed to "guess" a person's thoughts using fMRI (functional magnetic resonance imaging), although this requires samples of brain States. For example, if researchers registered a brain state when a person thought about a particular movie scene, they recognized that thought the next time.
However, neuroscientists still do not know how to recognize spontaneous thoughts. Instead, they try to answer the question "how" (rather than "what") a person thinks — for example, how to switch between different cognitive States or thoughts.
Jordan Poppenk and Julie Tseng of Queens University in Kingston have proposed a way to see the end of one thought and the beginning of another on fMRI. Neuroscientists collected fMRI recordings of 184 volunteers: they were either just resting or watching a movie. From each record, we isolated the activity of 15 known brain networks and simplified the dimension to two-dimensional. As a result, each state of the brain occupied a point on the plane, and the authors associated the resulting curve with the development of human thought: if the thoughts are disconnected, there will be separate points on the graph, and if the thought develops around a single topic, "worms" will appear — chains of States that are close in space.
To confirm the relevance of the model, the researchers tracked changes in brain States while watching the movie. To begin with, we built a diagram of transitions between States (the length of step vectors between two neighboring points on the graph) for recordings at rest and when watching movies. Then we compared each step of individual participants with the average value for the group.
It turned out that when watching the movie, the transitions between the States of different participants correspond to each other more than when at rest. This means that watching a movie causes similar activity in different people's brains; this connection has been observed in other studies. Moreover, the more events that took place in the film, the closer were the graphs of the transition States of different viewers. And for individual participants, transitions between States coincided with changes in scenes in the film (up to 60.8 percent of events in the film could be mapped to the corresponding transition).
Researchers analyzed which areas of the brain were activated at the time of transition between States and found that both at rest and when watching a movie when changing "thoughts" on fMRI, the same areas are active: the anterior and posterior cingulate cortex, preclinium, and insular lobe.
Finally, the researchers compared the number of transitions between States in different resting fMRI sessions at different times in the same volunteers. So the researchers checked whether the number of transitions is a stable characteristic inherent in a person. Indeed, the parameter was stable between different attempts and days (p <0.001), which means that it can be considered as a characteristic feature that persists regardless of mood fluctuations, fatigue, and other factors.
Since the results showed that a large number of transitions are associated with a large number of alternating thoughts, scientists assumed that a large frequency of transitions will be characteristic of neurotic people. Indeed, psychological and physiological characteristics were correlated (p = 0.027), and the transitions of neurotic volunteers when watching the film were less similar to other participants. The latter can be explained by the fact that people with neuroticism tend to be distracted, and their thoughts jump faster, for example, from one scene in a movie to another.
In conclusion, the authors calculated how many transitions — that is, new thoughts-occur per day. On average, participants had about 6.5 transitions per minute when they were at rest, which means that more than six thousand thoughts pass through their heads during the day. Scientists note that the created approach opens up wide prospects in the study of thinking, although more research is needed to speak confidently about the identity of transitions of brain States and new thoughts.
Last year, Russian researchers published an article in which they claimed that EEG can restore the video that a person is watching. On closer inspection, it turned out that the "mind-reading" was far away — scientists were only able to guess the type of image that the person saw. There were only five types, and the researchers first had to get a sample of brain activity in response to each of them. We talked about the experiment and the prospect of mind reading in the blog " neural Networks have learned to read thoughts in real-time. What? No!"