Are you Living in a Computer Simulation? (simulation-argument.com)

The following might be rubbish, but it also might be very relevant: http://prespacetime.com/index.php/pst/article/view/18

If you believe (I do), this one might give some pointers to you: http://www.transhumanist.com/volume7/simulation.html

This is a famous article of Nick Bostrom from 2002 (published in Philosophical Quaterly). I saw this first in a seminar on anti-realistic theories of truth.

If we are indeed living inside a simulation, what knowledge can we have about an external world?

You might also enjoy a discussion of the "brains in a vat" hypothesis: http://plato.stanford.edu/entries/brain-vat/

Somehow I feel like this explains the decline effect.