I've heard the term 'spot detector' thrown around in some of the brainscience literature, but I vaguely remember learning in university that there are no spot detector neurons in the brain, only on the retina.
So my first question is: are there or are there not spot detector neurons in the brain?
My second question is: if not, then how are we actually able to see spots or know about them? Doesn't being conscious of something require some kind of brain processing of that information? Doesn't the brain have to have some kind of 'detector' mechanism in place in order for us to perceive whatever's being detected? When I look at the stars I surely feel like I'm seeing spots (or points). Same with pencil marks on paper. What brain area is responsible for my perception of these things if not spot detectors?