Changes of cortico-striatal effective connectivity during visuomotor learning.
It has been suggested that the cortico-striatal system might play a crucial role in learning behavioural plans of action. We have tested this hypothesis by studying the dynamics of functional coupling among the neural elements of cortico-striatal circuitry. Human cerebral activity was measured with functional magnetic resonance imaging (fMRI) during the learning of an associative visuomotor task. Structural equation modelling of regional fMRI time-series was used to characterize learning-related changes in effective connectivity. We report that learning to associate visual instructions with motor responses significantly altered cortico-striatal functional couplings. Specific learning-related increases of effective connectivity were found in temporo-striatal and fronto-striatal circuits. Connectivity among portions of the frontal cortex decreased as a function of learning. Temporo-frontal and parieto-frontal couplings were not altered during learning. We infer that novel visuomotor associations are established through the enhancement of specific cortico-striatal circuits, rather than through the alteration of direct temporo-frontal or parieto-frontal connectivity.
Toni
Ivan
I
F.C. Donders Centre for Cognitive Neuroimaging, University of Nijmegen, NL-6500 HB Nijmegen, The Netherlands. ivan.toni@fcdonders.kun.nl
Rowe
James
J
Stephan
Klaas E
KE
Passingham
Richard E
RE
D002540:Cerebral Cortex / Q000502:physiology*; D003342:Corpus Striatum / Q000502:physiology*; D006801:Humans; D007858:Learning / Q000502:physiology*; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D009434:Neural Pathways / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*