The human brain is the evolved version of the reptilian brain as well as the brain of the other mammalian species. Behaviour as the functional expression of the brain has evolved from the genetic layer executed instinctive behaviour into the advanced cognitive brain executed voluntary as intelligent behaviour pattern.

Instinctive behaviour which is fixed in nature is executed by the automatic regions of the brain, which is genetically programmed. Cognitive as voluntary behaviour executed by the advanced cortex layer of the brain is a certain objective-oriented planned reaction pattern. Human voluntary behaviour is flexible and dynamic; we are capable of reacting according to the circumstances in a planned manner. Cognitively planned best voluntary behavioural strategy is evolutionarily adapted by the process of natural selection within the society.

There is a certain functional brain mechanism operational behind the context-dependent, flexible and dynamic human behaviour pattern. Through this thesis paper, we have tried to understand the mechanism of the functional brain, which executes human behaviour dynamically and in a context-dependent manner; and how human behaviour is evolving. We have proposed conceptual models of the functional brain to analyse as well as predict dynamic human behaviour. For example, why and how in the repeated functional context the same individual reacts differently; how advanced cognitive brain regions executed functional brain output transforms into brain automatic regions executed function, in the repeated functional context.

There are eight chapters in the thesis, where we have explained how human behaviour is executed flexibly by the functional brain process. We have proposed a three-step functional brain mechanism to analyse and explain dynamic human behaviour. Role of the memory system in the dynamic functional brain output; we have proposed a long-term memory system classification mechanism, based on the functional role played by the long-term memory system in the decision making process; based on this long-term memory classification have proposed a cognitive growth model, which is applicable in the context of analyzing individual-specific cognitive development. Have proposed a decision-making model to explain about how the decision-making process plays a role in the process of dynamic human behaviour. Finally, we have explained the role of the functional brain process in the process of human behavioural transformation.

This paper may facilitate those, who are working on such subjective areas, where a deeper understanding of cognitive psychology is necessary. For example, for professionals as well as students of the subjective fields like behavioural economics, management, consumer behaviour study, marketing research, strategic management, advertisement management, government policy-making, human behaviour study, or other related fields; cognitive psychology is the fundamental ground of all those subjective areas.