Main Question or Discussion Point
Regarding human vision and the retina:
Where are these channels produced? To put it simply, is it produced in the eye or in the brain. For example; does light enter the eye, hits the retina and it applies a series of filters to produce these 2 different channels (the parvo and magno) and it outputs this information to the brain via the optic nerve? Or does light enter the eye, hits the retina and it applies a series of filters, it excites certain ganglion cells that fire, those signals are grouped and output to the brain via the optic nerve and the brain is then responsible for converting this information into 2 channels; the parvo and magno?The retina model presents two outputs that benefit from the above cited behaviors.
- The first one is called the Parvocellular channel. It is mainly active in the foveal retina area (high resolution central vision with color sensitive photo-receptors), its aim is to provide accurate color vision for visual details remaining static on the retina. On the other hand objects moving on the retina projection are blurred.
- The second well known channel is the Magnocellular channel. It is mainly active in the retina peripheral vision and send signals related to change events (motion, transient events, etc.). These outing signals also help visual system to focus/center retina on 'transient'/moving areas for more detailed analysis thus improving visual scene context and object classification.