Post-hoc comparisons revealed significant differences for both phonemic and semantic VF between LFS ( MeanPvf-@ Hz = @ @ , MeanSvf-@ Hz = @ @ ) and HFS ( MeanPvf-ON = @ @ , MeanSvf-ON = @ @ , both P < @ ) , while DBS-OFF ( MeanPvf-OFF = @ @ , MeanSvf-OFF = @ @ ) and HFS and DBS-OFF and LFS did not differ significantly ( P > @ ) .