title: Why musical memory can be preserved in advanced Alzheimer's disease.
abstract: Musical memory is considered to be partly independent from other memory systems. In Alzheimer's disease and different types of dementia, musical memory is surprisingly robust, and likewise for brain lesions affecting other kinds of memory. However, the mechanisms and neural substrates of musical memory remain poorly understood. In a group of 32 normal young human subjects (16 male and 16 female, mean age of 28.0 ± 2.2 years), we performed a 7 T functional magnetic resonance imaging study of brain responses to music excerpts that were unknown, recently known (heard an hour before scanning), and long-known. We used multivariate pattern classification to identify brain regions that encode long-term musical memory. The results showed a crucial role for the caudal anterior cingulate and the ventral pre-supplementary motor area in the neural encoding of long-known as compared with recently known and unknown music. In the second part of the study, we analysed data of three essential Alzheimer's disease biomarkers in a region of interest derived from our musical memory findings (caudal anterior cingulate cortex and ventral pre-supplementary motor area) in 20 patients with Alzheimer's disease (10 male and 10 female, mean age of 68.9 ± 9.0 years) and 34 healthy control subjects (14 male and 20 female, mean age of 68.1 ± 7.2 years). Interestingly, the regions identified to encode musical memory corresponded to areas that showed substantially minimal cortical atrophy (as measured with magnetic resonance imaging), and minimal disruption of glucose-metabolism (as measured with (18)F-fluorodeoxyglucose positron emission tomography), as compared to the rest of the brain. However, amyloid-β deposition (as measured with (18)F-flobetapir positron emission tomography) within the currently observed regions of interest was not substantially less than in the rest of the brain, which suggests that the regions of interest were still in a very early stage of the expected course of biomarker development in these regions (amyloid accumulation → hypometabolism → cortical atrophy) and therefore relatively well preserved. Given the observed overlap of musical memory regions with areas that are relatively spared in Alzheimer's disease, the current findings may thus explain the surprising preservation of musical memory in this neurodegenerative disease.
authors.affiliation: 1 Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany 2 ISLA, Informatics Institute, University of Amsterdam, 1098XH Amsterdam, The Netherlands mail@henrik-jacobsen.com.
authors.forename: Jörn-Henrik
authors.initials: JH
authors.lastname: Jacobsen
authors.affiliation: 1 Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany 3 Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, 2650 Hvidovre, Denmark 4 Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Stelzer
authors.affiliation: 1 Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany 5 Department of Nuclear Medicine University of Leipzig, Liebigstrasse 18, 04103 Leipzig, Germany 6 Institute for Psychoacoustics and Electronic Music (IPEM), Blandijnberg 2, B-9000 Ghent, Belgium.
authors.forename: Thomas Hans
authors.initials: TH
authors.lastname: Fritz
authors.affiliation: 7 INSERM, U1077, Caen, France 8 Université de Caen Basse-Normandie, UMR-S1077, Caen, France 9 Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France 10 CHU de Caen, U1077 Caen, France.
authors.forename: Gael
authors.initials: G
authors.lastname: Chételat
authors.affiliation: 7 INSERM, U1077, Caen, France 8 Université de Caen Basse-Normandie, UMR-S1077, Caen, France 9 Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France 10 CHU de Caen, U1077 Caen, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: La Joie
authors.affiliation: 1 Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Turner
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D016229:Amyloid beta-Peptides / Q000378:metabolism; D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D003072:Cognition Disorders / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D009146:Music; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000379:methods
chemical_list: D016229:Amyloid beta-Peptides
keywords: Alzheimer’s disease; musical memory; preservation; ultra-high-field neuroimaging