Another article has just been passed on to me. It discusses an inverse relationship between waking and REM sleep eye movements. This may shed some light on the subject of whether eye movements used in EMDR may link into the same processes inherent in REM sleep:
De Gennaro, L., Casagrande, M., Violani, C., Di Giovanni, M. Herman, J. & Bertini (1995) The complementary relationship between waking and REM oculomotor system: an increase of rightward saccades during waking causes a decrease of rightward eye movements during REM sleep. Electroencephalography and clinical Neurophysiology, 95, 252-256