title: Altered Brain Activities Associated with Neural Repetition Effects in Mild Cognitive Impairment Patients.
abstract: Older adults with mild cognitive impairment (MCI) manifest impaired explicit memory. However, studies on implicit memory such as repetition effects in persons with MCI have been limited. In the present study, 17 MCI patients and 16 healthy normal controls (NC) completed a modified delayed-match-to-sample task while undergoing functional magnetic resonance imaging. We aim to examine the neural basis of repetition; specifically, to elucidate whether and how repetition-related brain responses are altered in participants with MCI. When repeatedly rejecting distracters, both NC and MCI showed similar behavioral repetition effects; however, in both whole-brain and region-of-interest analyses of functional data, persons with MCI showed reduced repetition-driven suppression in the middle occipital and middle frontal gyrus. Further, individual difference analysis found that activation in the left middle occipital gyrus was positively correlated with rejecting reaction time and negatively correlated with accuracy rate, suggesting a predictor of repetition behavioral performance. These findings provide new evidence to support the view that neural mechanisms of repetition effect are altered in MCI who manifests compensatory repetition-related brain activities along with their neuropathology.
authors.affiliation: Center on Aging Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.|Faculty of Psychology, Southwest University, Chongqing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.affiliation: Center on Aging Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: University of Kentucky, College of Medicine, Lexington, KY, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: University of Kentucky, College of Medicine, Lexington, KY, USA.
authors.forename: Lucas S
authors.initials: LS
authors.lastname: Broster
authors.affiliation: Center on Aging Psychology, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.|State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D060825:Cognitive Dysfunction / Q000473:pathology* / Q000523:psychology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011569:Psychiatric Status Rating Scales; D011930:Reaction Time / Q000502:physiology; D012111:Residence Characteristics
chemical_list: D010100:Oxygen
keywords: Delayed-match-to-sample task; functional MRI; mild cognitive impairment; repetition; repetition suppression