Looks like, the stress due to un-processed information has been treated so far as a subset of stress due to processed information.
Came across a review of Alex Wright's book Glut in Nature while checking some cross-references (technical), which mentioned that a google search for information overload comes up with millions of results; so had to go and try it; I got about 49000hits in 0.2 sec; anyways, the interesting finding is that Reuters conducted a survey in 1996 and the report is called Dying for Information?
So basically, the relation between information and stress is for real. I need to deal with trying to define un-processed information. The terms un-organized, un-structured and even un-categorized information would probably qualify as un-processed to varying degrees. At least this seems to be what information overload is concerned with; particularly when you are surveying people. I feel, the origin has to be much more subtle. When we leave something un-categorized, there's an absence of a very specific piece of information that we did not seek and this, I feel is the stressor. Anyways, hopefully the thoughts will evolve and become clearer; will try to get hold of a copy of Glut meanwhile. Whats known about the biochemical cycle seems to be much more elusive though. The role of language in processing information also becomes relevant. A large part in the difference between processed and unprocessed info can be estimated by the words that would be used to describe a visual signal for example. So, the conversion of a visual signal into words maybe an interesting biochemical cycle to explore.