Human brain is acknowledged to be the most complex structure in the known universe. Technology has advanced so much in the recent years that it has helped the mankind learn more about it in the last two decades than in the entire human history.

One of the biggest contributors for such progress has been the ability of various imaging techniques in neuroscience, which can detect activity within the human brain without invasive surgery. It has also helped the human brain to be mapped in minute details.

Despite such progress, knowledge about fundamental workings of the brain is still a mystery. Very little is known about mechanisms underlying phenomena like thinking, memory, emotions, attention, consciousness, sleep, dreams, multi-tasking, etc.

The core reason for lack of such fundamental knowledge is that like other sciences of mind and brain, neuroscience does not study the brain as one integrated system.

The Brain-as-a-System Approach

Anything that has multiple parts which work collectively to reach common goals has to be driven by a system. Such multiple parts cannot work independently and still reach common goals.

This simple and fundamental fact is not taken into consideration by neuroscience, which studies various aspects of brain’s workings in great details, but does not see it as one integrated system.

The current approach of neuroscience to understand workings of the brain is by breaking it down into its components and study them, for which it follows a linear approach, i.e. from problem to solution.

Most components of the brain are interdependent and do not work in a linear fashion.

What is needed is a holistic approach of a goal driven system which studies how brain’s components interrelate and interact with each other, while interacting with other external systems and components, i. e., a system approach.

Secondly, different parts of the brain work together in goal-driven activities, implying that they work in causal manner, whereas neuroscience relies mainly on correlations. Correlations do not imply causation. To understand and control the world around us, it is important to know what causes what. Once we understand the causal connections of a system, we can explain what has happened in the past, predict what will happen in the future and intervene to seek the outcomes we desire.

Based on the above points, one can derive that the best way to understand how the brain works is through a 1) causal account of a 2) single integrated system.

The first comprehensive effort to study the entire brain as one causal system has resulted in the development of Dichotomized Operating System Model, a functional model which reveals a system consisting of multiple hierarchically interconnected goal-driven software mechanisms and processes running in the brain that form what we collectively call "mind".

It is the only existing causal account of the human mind and is based on the mechanism of Natural Selection proposed by Charles Darwin in the year 1859 in his book "On the Origins of Species - By Means of Natural Selection".

Natural Selection works on the premise that nature selects, i.e. favours, organisms for survival based on their inheritance of characteristics that allow them to survive and reproduce better than other organisms of their species that do not have such characteristics. Continuous addition and optimization by favouring better and better survival and reproduction characteristics in every passing generation for a period of millions of years has resulted into organisms accumulating a high number of highly optimized characteristics favouring survival and reproduction based on their environments and ecosystems, which has been responsible for the human body to develop in highly optimized manner.

According to the DOS model, the process of natural selection is not only responsible for physical development, but also mental development, as it has the same physical basis and is a part of the same goal-driven activity.

To demonstrate the same, the model uses a single framework of hierarchically interconnected mechanisms to coherently explain diverse mind phenomena like thinking, awareness, attention, sensations, perception, consciousness, decision-making, multitasking, instincts, etc., along with day-to-day life phenomena like happiness, desire, feelings, attitude, moods & emotions, imagination, intuition, sleep, dreams, humour, love, sex, art, taste, music, etc.

If such mechanisms are mapped to their respective processing areas in the brain, which can be done by the capability of neuroscience to correlate mental activity with its associated brain activity, it will help in resolving a range of problems spanning from day-to-day life phenomena to diagnosing and treating mental illnesses and disorders (e.g. Autism, Multiple Personality Disorder, etc.) in less cumbersome, more reliable and most importantly, fully conclusive manner.

Integrating the model will also make it possible to conduct transdisciplinary research, thereby connecting all mind and brain sciences (e.g. neuroscience to psychology) through the common grounds of causation. Such integration will be especially useful considering the fact that despite engaging in multidisciplinary and interdisciplinary studies, several big-ticket projects like Human Brain Project, BRAIN Initiative, The Blue Brain Project, The Human Connectome Project, etc. are unable to pool their findings, making it difficult to bring them to conclusive outcomes.

The fact that only two core components of the model are the driving force (hence the name dichotomized), and thus are sufficient to explain mechanisms underlying all mind phenomena makes it easy for the common man to understand the model, and thus workings of his own mind, giving a new meaning to the term introspection.

Understanding purpose and workings of mental mechanisms can bring about revolution not only in sciences related to the human mind and brain, but human life as a whole.

No prior knowledge of any subject is required to understand the model.