In our brains, associations are formed by joining synapses (memory nodes) based on their usage in direct and referential associations. This joining is done by the neurotransmitter dopamine, a neurochemical that physically burns-in the synaptic pathways in order to wire neurons together, thereby forging the associative link between concepts.

Dopamine is a feel-good drug that creates an obsessive-compulsive behavior to complete an action for closure or completeness and therefore sets up the duality of motivation by learning and learning by motivation. As a side note, it's interesting to note that dopamine also forms the basis for drug and other types of addiction, so it's an extremely powerful motivator.

There are limits to how fast and how much we can learn at any one time. We're limited by our ability to subitize up to three items. Subitizing is an innate characteristic shared not only by humans, but also by all living (conscious) creatures. For example, research has shown that a new baby has the ability to subitize, defined as the immediate conceptualization of the relationship between an item of focus and its two adjacent items, automatically and subconsciously.

Surprisingly, or not surprisingly as the case may be, research has shown that all animals can subitize at a very early age, but some have the ability to leverage subitization more than others through levels of abstraction as they mature. The difference in what we call higher-order beings, such as humans (and apes), is that language permits us to lock-in higher order concepts and then to abstract and communicate those concepts as concepts of concepts, etc, for knowledge leveraging and sharing. In effect, common language abstraction (vocabulary) becomes the difference as language provides the ladder to superior intelligence as we know it.

Subitized relationships are abstracted into associated concepts in hierarchies of 7+/-2 as limited by short-term memory (frontal lobe). To make room in the frontal lobe for more information with which to understand the world around us, we use language abstraction to associate higher-order concepts that we then associate with concepts in our mid and long term memory. This process facilitates the storage and organization of our memory and our respective mid and long-term knowledge, where short-term memory effectively becomes a knowledge management scratchpad.

Did you hear that?
But how does this all work in the brain? A good way to help you create an image of the process is to describe what happens, according to research, when we hear and respond to conversation.

From an auditory perspective, we pick up sounds with our inner ear. The Broka's area behind the ear serializes the sound waves and passes them off to Wernicke's area, which in turn normalizes the serialized sound frequencies into base frequencies that the brain's central motor management region, the basil ganglia, can deal with. Consider it like music resonating a common chord in the same octave.