Cerebellar-parietal connections underpin phonological storage.
Previous research has accumulated convincing evidence to show that the human cerebellum contributes to the short-term storage of verbal information, but its specific role in brain networks involved in phonological storage remains uncertain. In a randomized, crossover and sham-controlled design, we here combined transcranial direct current stimulation (tDCS), applied to the right cerebellum, with fMRI to investigate systematically the contribution of the human cerebellum to encoding, maintenance, and retrieval of verbal information. After anodal, but not cathodal, tDCS, we found a reduced item recognition capacity together with an attenuated neural signal from the right cerebellar lobule VIIb, specifically during the late encoding phase. Within this phase, tDCS furthermore affected task-associated functional connections between right cerebellar lobule VIIb and the posterior parietal cortex. These findings suggest that the right cerebellar lobule VIIb interacts with the posterior parietal cortex, specifically during the late stages of verbal encoding, when verbal information enters phonological storage.
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany, Clinic for Psychiatry and Psychotherapy, Central Institute for Mental Health, 68159 Mannheim, Germany, Berlin School of Mind and Brain, Mind and Brain Institute, 10099 Berlin, Germany, and Clinic for Cognitive Neurology, University Hospital Leipzig, 04103 Leipzig, Germany.
Katja
K
Macher
Andreas
A
Böhringer
Arno
A
Villringer
Burkhard
B
Pleger
D000328:Adult; D001931:Brain Mapping; D002531:Cerebellum / Q000098:blood supply / Q000502:physiology*; D018592:Cross-Over Studies; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008297:Male; D009434:Neural Pathways / Q000098:blood supply / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000098:blood supply / Q000502:physiology*; D010700:Phonetics; D014706:Verbal Learning / Q000502:physiology*; D055815:Young Adult
D010100:Oxygen
brain connectivity; cerebellum; functional magnetic resonance imaging; noninvasive brain stimulation; posterior parietal cortex; verbal working memory