Cognitive control over motor output in Tourette syndrome

► PFC should be viewed as a source of facilitatory signals that bias competition in brain areas more directly involved in motor execution. ► In TS over-activation of PFC may contribute to the hyper-excitability of motor regions and the occurrence of tics. ► Compensatory changes, leading to enhanced cognitive control in TS, may primarily be implemented by distributed changes in local cortical excitability.