Previously titled as “Why entropy is messing with our brain”.

The mind, no different from a dynamic system, searches for its lowest possible energetic state reducing so the entropy of themind&bodyas a whole, known in neuroscience as theFree-Energy Principle(FEP)(Cieri et al.). However, from a neuropsychological perspective, what does entropy mean? And why it’s so important? Well, answering the first question, entropy represents the unknown for the brain. It is the set of external inputs that are not accounted for or expected by it. This is key to understanding some of the most severe neuropsychiatric diseases.

Our brain works in a very curious way, quite unexpected even, but very efficient. When it is not focused on cognitive tasks we can say that it is in aRESTstate (Random Episodic Silent Thinking). This is a continuous state represented by a stream of consciousness where our brain is invested in our memories, daydreaming, emotions, body sensations, future imaging, and dynamic simulation of scenarios, among others. There are parts of our brain that are devoted (and by this I mean active) in this state, deduced throughout the decades using MRI or other imaging techniques.

In this interpretation the brain works as aBayesian system, where it has a baseline model of the external world subjected to updates and predictions. However, this steady-state can be disrupted by any cognitive task. In reality, there are two types of disturbances that should be accounted for: evoked and spurious. So, any type of external activity that requires cognitive focus evokes a response with a certain frequency plus our random brain activity.

The brain’s model of the external world is adapted and updated to minimize any possible “surprise” that could affect our system and hence, increase the entropy. To do this, it is fundamental to have an accurate prediction system as well as find simplified explanations to our sensorium. In the end, the objective is to have the less complex and more accurate justifications that can integrate our internal state with our sensory impressions.

freeEnergy = complexity — accuracy

In terms of brain anatomy, the neural network that is active during REST is the DMN (I won’t be disclosing the constituents because no way you are going to remember,#hardtruth) it is considered a task-negative network because it is inactive when cognitive efforts are taking place. In parallel we have the DAN, which is task-positive and therefore active during cognitive tasks. Both of these networks are in an anti-correlation relationship. It was proved that the nature of this relationship changes over the physiological aging process. It is consolidated when the child has around two years and is very important in the transition to adulthood, growing stronger. It deteriorates at a mature age as an inclination towards neuroaging, cognitive weakening, and loss of self-functions (Cieri et al.).

If one would like to relate this to something more tangible (in a brain sense, if that is even possible), we have for example a Schizophrenic brain that has a big difficulty in recognizing self-referential activities, hypo-activation for mental simulations and lack of dream and predictive activities. In an Alzheimer’s brain what we have is a hypo-connectivity of components of the DMN network, leading to impairment in self-generated cognition. On the other hand, in a depressive or ADHD brain what one has is hyper-activation and an excessive amount of self-generated thoughts. So, these relations are quite clear and are far more important than one could have imagined (Cieri et al.).

So in the end, we could say that “craziness” comes from the inability to digest the external world. I find it quite groundbreaking that it has so little to do with how you perceive yourself and so much to do with your ability to develop the connection between your identity (seen from Freud’s point of view) and the external world.

Well, talking about Freud (we’ll tackle that guy eventually), and to put it into perspective, personality disorders happen when one is unable to perform the integration of the self. I’m very curious about one condition in particular, the Borderline Personality. It is related to a split between an “ideal world” and a “prosecutory world” whereby projection one ends up not accepting the prosecutory one as reality and hiding in the “ideal world”. I’m not quite sure, but I assume that this condition should have a scale to measure the dangerousness of your mental disorder,or something. Because I don’t know you, but I spend a hell of a lot of time in my “ideal world”.I guess what I’m trying to say is that I hope I’m not crazy.