As visual information passes from the retina to the optic nerve, the lateral geniculate nucleus, and then to the primary visual cortex, it is processed in a hierarchical manner; e.g., photoreceptors in the retina respond to light levels over small regions of visual space, while higher cortical visual areas respond selectively to more complex objects such as faces.
Related content
The olfactory system detects airborne odor molecules in the nasal cavity and transmits this information to the olfactory bulb. From there, signals are relayed to several brain regions involved in smell perception, memory, emotion, and behaviour.
The gustatory system detects taste stimuli on the tongue and relays this information through brainstem and thalamic pathways to the gustatory cortex.
Movement is controlled by a network of brain and spinal cord structures that work together to plan, initiate, coordinate, and execute actions.