title: Stuck in default mode: inefficient cross-frequency synchronization may lead to age-related short-term memory decline.
abstract: Aging-related decline in short-term memory capacity seems to be caused by deficient balancing of task-related and resting state brain networks activity; however, the exact neural mechanism underlying this deficit remains elusive. Here, we studied brain oscillatory activity in healthy young and old adults during visual information maintenance in a delayed match-to-sample task. Particular emphasis was on long range phase:amplitude coupling of frontal alpha (8-12 Hz) and posterior fast oscillatory activity (>30 Hz). It is argued that through posterior fast oscillatory activity nesting into the excitatory or the inhibitory phase of frontal alpha wave, long-range networks can be efficiently coupled or decoupled, respectively. On the basis of this mechanism, we show that healthy, elderly participants exhibit a lack of synchronization in task-relevant networks while maintaining synchronized regions of the resting state network. Lacking disconnection of this resting state network is predictive of aging-related short-term memory decline. These results support the idea of inefficient orchestration of competing brain networks in the aging human brain and identify the neural mechanism responsible for this control breakdown.
authors: Department of Clinical Psychology and Psychobiology, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain; Department of Psychology, University of Surrey, Guildford, United Kingdom.
authors: Diego
authors: D
authors: Pinal
authors: Department of Clinical Psychology and Psychobiology, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain.
authors: Montserrat
authors: M
authors: Zurrón
authors: Department of Clinical Psychology and Psychobiology, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain.
authors: Fernando
authors: F
authors: Díaz
authors: Department of Psychology, University of Surrey, Guildford, United Kingdom; Department of Psychology, Ludwig-Maximilian-University Munich, Munich, Germany. Electronic address: paul.sauseng@lmu.de.
authors: Paul
authors: P
authors: Sauseng
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology*; D001921:Brain / Q000502:physiology*; D003344:Cortical Synchronization / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000209:etiology* / Q000523:psychology*; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D013647:Task Performance and Analysis; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Brain networks; Cross-frequency synchronization; Normal aging; Oscillations; Short-term memory