The basal ganglia-thalamocortical circuits that are affected in Progressive Supranuclear Palsy (PSP) and Corticocbasal Ganglionic Degeneration (CBGD) are likely structurally and functionally segregated. The 'motor' circuit is implicated in parkinsonian akinesia and hypokinesia; a 'prefrontal' circuit is implicated in working memory and mood regulation, and linked with non-motor symptoms such as depression and apathy. In this proposal, we characterize motor and prefrontal network dysfunction in PSP and CBGD patients, and propose that high-frequency and low-frequency rTMS directed over separate motor and prefrontal cortical targets of each network may show specific and selective beneficial effects on motor vs. cognitive function in PSP and CBGD patients, respectively. Quantitative motor outcome measures include timed finger tapping tasks. Quantitative cognitive outcome measures comprise a visual analogue scale (VAS).