Discrete fnger sequences are widely represented in human striatum

Research in primates and rodents ascribes the striatum a critical role in integrating elementary movements into unitary action sequences through reinforcement-based learning. Yet it remains to be shown whether the human striatum represents action sequence-specifc information. Young right-handed volunteers underwent functional magnetic resonance imaging while they performed four discrete fnger sequences with their right hand, consisting of fve button presses. Specifc fnger sequences could be discriminated based on the distributed activity patterns in left and right striatum, but not by average diferences in single-voxel activity. Multiple bilateral clusters in putamen and caudate nucleus belonging to motor, associative, parietal and limbic territories contributed to classifcation sensitivity. The results show that individual fnger movement sequences are widely represented in human striatum, supporting functional integration rather than segregation. The fndings are compatible with the idea that the basal ganglia simultaneously integrate motor, associative and limbic aspects in the control of complex overlearned behaviour.