By accident, any other models can enter the PSM, but some of them can produce big problems for the future mature being, mainly paranoia type illnesses (see ETAs). The basic characteristic of any model from the PSM is that such a model is invariant. It cannot be changed regardless of the information obtained from the external reality. The main goal of the PSM is to ensure that the being will survive unconditionally, forever. To do this, the PSM is able to build elements, which are activated to self-develop as models. So, when a new situation from the external reality is met, and there is no model to understand it, the PSM is automatically activated and tries to solve the problem, based on some reflex actions, or based on some instincts. It also makes a specialized element, which is activated as a model. The new model tries to understand the new situation by independent activity, in interaction with the external reality. When that situation is met again, the PSM is not activated, and the specialized model solves the case. So, as a being gains more and more experience, the PSM is not activated, but one of the specialized models is activated instead. Regardless of how many models are in a brain, if a new external reality occurs and there is no model to understand it, the PSM will take the control in the way already described. When PSM controls a being, this can be recognized by the fact that the consciousness disappears, as the normal structure of models is deactivated by the PSM. This situation is called as shock-status. THE STRUCTURE OF THE BRAIN: FUNCTIONAL FACILITIES AND TYPES OF MODELS A basic functional facility of the brain is that any model can develop any of its elements as a model. Once a model activates an element, that element is able to develop itself as a model, by direct interaction with the external reality and with any other model of the brain. Another functional facility is described here. We see that a model can activate any of its elements to develop itself as a model. But, even if an element is already developed as a model, the main model continues to treat it as an element. This important feature will be developed below. So, a main model has an element. This element has some properties. To integrate that element, the main model uses these properties. Now, the problems could be like: "why that element has such properties?" or "how such properties can be changed?" To answer such questions, the main model has to develop the element as a model. Once an element is developed as a model, its properties appear to be truths generated by the model. So, depending of the point of view, referring to the same entity, we discuss about an element with some properties, or about a model with some associated truths.