Post-hoc comparisons revealed significant differences for both phonemic and semantic VF between LFS ( MeanPvf-10 Hz = 54.6 9.2 , MeanSvf-10 Hz = 56.4 7.9 ) and HFS ( MeanPvf-ON = 48.3 11.4 , MeanSvf-ON = 51.1 11.0 , both P < .05 ) , while DBS-OFF ( MeanPvf-OFF = 51.2 9.3 , MeanSvf-OFF = 53.6 12.9 ) and HFS and DBS-OFF and LFS did not differ significantly ( P > .05 ) .