Complex sentence: Using the technique on those familiar with it may still cause an instinctive psychological response, however as they are aware of the attempted manipulation they may just close-down entirely or try to disrupt the procedure (see below).
Split into simpler sentences: Using the technique on those familiar with it may still cause an instinctive psychological response. However, as they are aware of the attempted manipulation, they may just close-down entirely or try to disrupt the procedure (see below).