apparently, different parts of our brain are used to process information involving different senses. smell and taste are chemoreceptions, closely related to the limbic system, an ancient part of the brain. touch, sound and sight are related to the cortices.
vision is processed in the occipital lobe (back of the head);
audition is processed in the temporal lobes (sides of the brain);
sensation is processed in the parietal lobe (top of the brain, slightly towards the back of the head);
taste is processed in the insular cortex (middle of the temporal lobe);
smell in the orbitofrontal lobe (front and bottom, near the eyes and nose)