Design: Ten individuals with PSP and ten with CBGD will participate in a within-subject cross-sectional design. Motor outcome measures include a timed finger tapping task at comfortable and maximal speed. Quantitative cognitive outcome measures comprise a visual analogue scale of mood states (VAS). After a first baseline visit, PSP patients will receive high-frequency 5 Hz rTMS in two separate visits to two site conditions (left DLPFC vs. the more affected side of M1) across subjects with two within-session task conditions (motor vs. cognitive). They will also receive sham stimulation in a separate visit. These three stimulation visits will be randomized. CBGD patients will receive the same treatment with the only difference that they will receive low-frequency 1 Hz rTMS instead.