Recall that the island effects are understood as the effects on acceptability of processing both longdistance wh-dependency and island structure contained in a single sentence like (1d) above (see Fodor (1983), Stowe (1986), Kluender (1998Kluender ( , 2004, and more recently Hofmeister & Sag (2010) for the studies on L1 processing of whdependencies; Juffs & Harrington (1995;, White & Juffs (1998), Williams et al (2001), and Juffs (2005) for the studies on their L2 processing).
the combined effects of the two factors are greater (i.e.