How do receptive fields become more complex from sensory receptors to the cerebral cortex?

The transformation of receptive fields from sensory receptors to the cerebral cortex follows a serial and hierarchical organization, where each stage of the nervous system integrates inputs to create increasingly complex stimulus requirements.1

In the sensory periphery, receptive fields are often simple, such as the circular, concentric on-centre/off-surround structures found in the retina and the lateral geniculate nucleus (LGN). These structures are primarily designed to detect local contrast.12

As information reaches the primary sensory cortex, these simple inputs are combined to detect more sophisticated features. For instance, in the primary visual cortex (V1), neurons transition from circular receptive fields to those selective for specific orientations, such as lines and edges. This complexity continues to increase in higher cortical areas:12
* Visual System: Neurons progress from detecting simple edges to responding to complex stimuli like motion, colour constancy, or even specific objects such as faces.12
* Auditory System: Peripheral neurons may respond to pure tones, while central neurons become tuned to more complex, frequency-modulated sounds.1

Ultimately, a neuron's receptive field is defined by the combination of all synaptic inputs feeding into it, allowing the brain to abstract and classify increasingly intricate information from the environment.12