title: Interference with existing memories alters offline intrinsic functional brain connectivity.
abstract: The notion that already existing memories can be modified after their reactivation has received an increasing amount of experimental support, with empirical data accumulating across species and memory paradigms. However, there is no evidence for systems-level task-free intrinsic signatures of memory modification. Here, using a combination of behavioral, brain stimulation, and neuroimaging paradigms, we report that noninvasive transcranial magnetic stimulation interference with a reactivated motor memory altered offline task-free corticostriatal interregional functional connectivity, reducing it compared to stimulation in which the reactivated memory was intact. Furthermore, the modulated functional connectivity predicted offline memory modification. This reduction in functional connectivity recovered after additional execution of the memorized task, and the interference did not affect control cerebellar-cortical functional connectivity. This demonstrates that intrinsic task-free offline brain activity can be modulated by noninvasive interaction with existing memories and strongly correlates with behavioral measurements of changes in memory strength.
authors.affiliation: Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: censorn@ninds.nih.gov.
authors.forename: Nitzan
authors.initials: N
authors.lastname: Censor
authors.affiliation: Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Silvina G
authors.initials: SG
authors.lastname: Horovitz
authors.affiliation: Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: cohenl@ninds.nih.gov.
authors.forename: Leonardo G
authors.initials: LG
authors.lastname: Cohen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000473:pathology*; D009415:Nerve Net / Q000098:blood supply / Q000503:physiopathology*; D009434:Neural Pathways / Q000098:blood supply / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D011597:Psychomotor Performance; D050781:Transcranial Magnetic Stimulation / Q000009:adverse effects; D055815:Young Adult
chemical_list: D010100:Oxygen