Writing question

[No Name Available]

A number of studies in reading research emphasize the importance of visual
perception and visual discrimination.  At the earliest stages of reading
(readiness),  children are taught these skills through recognition of the
shapes of words (configuration clues).  Only lowercase letters are used, for
they have the most distinguishable shapes, for example, curly tails (g's),
ascending and descending lines,  and circles.  The ability to recognize these
patterns promotes rapid word recognition, or quick perception,  and visual
dicrimination among beginning and mature readers, both of whom employ some
form of perception and discrimination as  reading strategies.   When all caps
are used, however, visual perception is impeded, for most of these
distinguishing characteristics are lost, and so, too, is the ability to
readily differentiate one letter from another (again, visual discrimination).
  In essence,  in passages with all caps, everything is salient!  There is no
background.

Since perception is a term borrowed from psychology, you might check not only
reading research on visual perception and discrimination but also figure
ground studies.
                                PAT