Over the next decade, PPS and PPAS continued to grow, and in 1966, Minsky and Simon published an article titled Brain Activity Systems, which was the result of their research. Here they showed that there was a program that could be written that would read the brains of a number of volunteers and then track their brain activity. Each volunteer read a passage about how the brain works; they had to complete this task, and then measured the activity of the brain.

Specifically, the authors showed that their system is capable of responding to certain brain waves (also called rhythms) and that it can combine these brain waves in ways that help make sense of a subject. They showed that if the brainwave was a slow rhythm, the system was able to «remember» information it was exposed to earlier and «reactivate» it when needed. If the brainwave was a fast rhythm, the system could «cure» the forgetfulness of information by comparing it with another element.

When Minsky and Simon published their article, they have attracted a lot of attention, because they offered this kind of experimental system, which theoretically can be implemented. They were able to approach the study from the practical point of view.

In 1972, Minsky and Simon founded the Center for Behavioral Neuroscience in Ann Arbor, Michigan. They designed and conducted a series of experiments that led them to the following conclusions: «There was something different from the mind, something that distinguished it from any other organization»; «The data showed that our ideas about action and the brain were different»; «Our brain worked differently than other parts of the body»; «There is a possibility that the organization of the mind may be influenced by the activity of the brain»; «The minds are based on basic physical principles.»

They came to this conclusion because they saw the relationship between specific brain activity and a specific behavior or idea. In other words, if you go to the mind and see activity that looked like it came from the mind, and you saw behavior that looked like it came from the mind, then the behavior is likely to follow the behavior. And if the mind was «imprinted» on the behavior, then it had to follow the action, and not vice versa. They began to formulate a new theory about how behavior arises and how mind is formed.

Minsky explained:

«The starting point was the work we did on the correlations between brain activity and human behavior. It was very clear to us that these correlations cannot be understood without first understanding how behavior is generated.»

The authors came to the conclusion that any inorganic system can act only on the basis of its internal states. If the internal states changed, then the behavior of the system would change. When the authors thought of a brain that responds to certain types of brain waves, they noticed that the brain would produce a certain behavior, and that this behavior would correspond to the internal state of the brain. This is a universal principle of nature. Since this principle of nature made behavior universal, it should lead the authors to the conclusion that if they applied these principles to the brain, they could create a computer program that would be able to reproduce the behavior of the brain.

Minsky believed that universal principles governing biological systems could be used to create computer software. However, Minsky admitted that his ideas were «science fiction.» It took Minsky and Simon another year to find a way to create a computer that could mimic their discoveries. But by 1972, they had developed a computer program that could test their theories.