Georgina Woodward
A single photon delivers a frequency. Groups of photons deliver intensity too. Identification of movement, for example) is generated from the spatial change in the pattern of receipt.
Quote- "bottom-to-top processing of our visual world may seem the logical path, but it isn’t the whole story. Such a 'bottom-up' approach would be far too slow and laborious, but more importantly, it would render our visual world full of ambiguity and we would struggle to survive. Instead, our perception relies to a very large extent on our previous experience and other 'top-down' mechanisms such as attention. QBI Professors Jason Mattingley and Stephen Williams are both studying how attention can alter visual processing, using cognitive and cellular approaches, respectively-- Visual perception - Queensland Brain Institute - University of Queensland
qbi.uq.edu.au
Max-Planck-Gesellschaft https://www.mpg.de/10518004/from-retina-to-cortex
'From retina to cortex: An unexpected division of labor'