Plasticity: brain plasticity is a term which is used to refer the brain's unique ability to constantly change, grow, and remap itself over the course of a lifetime. The “plastic” in this sense refers to “moldable,” rather than to the family of products derived from petrochemicals. This distinctive trait makes the brain a very valuable organ, as it can constantly adapt itself to deal with new input and information. All animals possess this characteristic to some extent, although most studies have focused specifically on the workings of the human brain.

Lateralization: the lateralization of human brain is the idea that the left and right sides of the brain carry out and regulate a variety of different functions and behaviors. Each of the two hemispheres is responsible for a distinct set of duties in brain lateralization; the left side handles analytical, logical, and verbal thought processes while the right oversees more sensitive processes, like feelings, intuition, and sensory matters. The duties of the two hemispheres are reversed in left-handed individuals. The thought that the two hemispheres manage these brain functions and behaviors for the overall operation of the individual and can be utilized as a situation demands is the theory behind brain lateralization.

Autonomy: autonomy is a complex socio-cognitive system, subject to internal and external constraints, which manifests itself in different degrees of independence and control of one’s own learning process. It involves capacities, abilities, attitudes, willingness, decision making, choices, planning, actions, and assessment either as a language learner or as a communicator inside or outside the classroom. As a complex system it is dynamic, chaotic, unpredictable, non-linear, adaptative, open, self-organizing, and sensitive to initial conditions and feedback.