To ask the question expecting an answer expressed in Megabytes &c is
barking up the wrong tree since the term refers to
quantities/magnitudes expressed by a *digital* number system. As
most information reaching the brain is expressing quantitative
information - intensity of light falling on optic receptors &c, in
terms of continuously variable *frequencies* of pulse recurrence,
"megabytes" are irrelevant. To achieve this in the way computers
do would require an infinite number of Gigabytes in the RAM!
Cheers! Gord