Repetition suppression and plasticity in the human brain.
The suppression of neuronal responses to a repeated event is a ubiquitous phenomenon in neuroscience. However, the underlying mechanisms remain largely unexplored. The aim of this study was to examine the temporal evolution of experience-dependent changes in connectivity induced by repeated stimuli. We recorded event-related potentials (ERPs) during frequency changes of a repeating tone. Bayesian inversion of dynamic causal models (DCM) of ERPs revealed systematic repetition-dependent changes in both intrinsic and extrinsic connections, within a hierarchical cortical network. Critically, these changes occurred very quickly, over inter-stimulus intervals that implicate short-term synaptic plasticity. Furthermore, intrinsic (within-source) connections showed biphasic changes that were much faster than changes in extrinsic (between-source) connections, which decreased monotonically with repetition. This study shows that auditory perceptual learning is associated with repetition-dependent plasticity in the human brain. It is remarkable that distinct changes in intrinsic and extrinsic connections could be quantified so reliably and non-invasively using EEG.
Garrido
Marta I
MI
Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, UK. migarrido@ucla.edu
Kilner
James M
JM
Kiebel
Stefan J
SJ
Stephan
Klaas E
KE
Baldeweg
Torsten
T
Friston
Karl J
KJ
D000161:Acoustic Stimulation; D000223:Adaptation, Psychological / Q000502:physiology; D000328:Adult; D000465:Algorithms; D001303:Auditory Cortex / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology*; D001499:Bayes Theorem; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009473:Neuronal Plasticity; D013702:Temporal Lobe / Q000502:physiology; D055815:Young Adult