Similarly , VFT scores significantly improved among all treatment groups , but the magnitude of improvement in the VFT score was significantly ( P < 0.0001 ) greater in the HF group ( 7.7 1.1 words/60 s ) than in the IF ( 3.6 1.2 words/60 s ) and LF ( 1.3 0.5 words/60 s ) groups .