Final answer:
The dorsal column system and the spinothalamic tract are the two main pathways transmitting sensory information to the cortex, specialized in touch and proprioception, and pain and temperature, respectively. Both follow a three-neuron progression and involve contralateral projection before reaching the somatosensory cortex.
Step-by-step explanation:
The two main pathways to transmit sensory information to the cortex are the dorsal column system, also known as the dorsal column-medial lemniscus, and the spinothalamic tract. These pathways are part of the ascending tracts that carry peripheral sensations to the brain. The dorsal column system is responsible for touch sensations and proprioception, which is the body's ability to perceive its own position in space. On the other hand, the spinothalamic tract mainly deals with pain and temperature sensations. Both pathways start with neurons in the dorsal root ganglions and consist of three successive neurons. The first neuron carries the sensory signal to the central nervous system, the second neuron crosses over to the opposite side of the brain or spinal cord (contralateral), and the third neuron projects to the somatosensory cortex from the thalamus.
In terms of processing, sensory stimuli are recognized at the primary sensory cortex, followed by processing in associative areas, and eventually integration in multimodal areas of the cortex. Such sensory processing provides vital information for motor responses and memory incorporation.