There are many different conceptual models of the brain. It’s important to note that many of them lack any scientific basis – this does not, however, negate the fundamental importance of these models. They are not there to “prove” anything but rather to stimulate creative thought as to how designers (and others) may offer all-round stimulation of the mind and create better experiences for it.
The three most commonly used models of the brain are the left-brain, right brain model, the triune brain model and the system 1, system 2 model. Despite their dubious scientific basis, they are still invaluable tools for designers; not as defined ways for the brain to work but rather to contemplate which parts of the psyche we are trying to communicate with and to see if our communications are fully inclusive or intentionally slanted.