Final answer:
Magnocellular RGCs transmit information about form, movement, depth, and brightness, while parvicellular RGCs relay details on color and fine detail. This visual information is processed through different brain areas like the thalamus and visual cortex to determine 'where' and 'what' in our visual field. Additionally, some RGCs influence the circadian rhythm by conveying light presence to the suprachiasmatic nucleus.
Step-by-step explanation:
Magnocellular and parvicellular retinal ganglion cells (RGCs) play distinct roles in sending visual signals to the brain. The magnocellular cells are responsible for transmitting information about form, movement, depth, and brightness differences, which is crucial for perceiving the general layout and motion within a visual scene. On the other hand, the parvicellular cells focus on transmitting detailed information about color and fine detail, which is vital for recognizing specific features of objects.
Once these visual signals reach the brain, they go to the thalamus, which acts as a routing station. The processed information is then sent to the primary visual cortex at the rear of the brain. From there, magnocellular information projects to the parietal lobe, aiding in understanding 'where' an object is, while both magnocellular and parvicellular information projects to the temporal lobe, helping to recognize 'what' the object is.
The distinct crossing of their pathways at the optic chiasma allows for the coordination of visual information from both eyes.
In addition to these pathways, a small number of RGC axons project to the suprachiasmatic nucleus of the hypothalamus, which is instrumental in regulating the circadian rhythm based on the presence or absence of light.