Scientific Reports 7, Article number: 16759 (2017)
DOI: 10.1038/s41598-017-12489-y
Andrea Berencsi1,2, Róbert Bódizs1,3,4, Ferenc Gombos1,3, Szandra László1,5, Ilona Kovács1,3
1 Laboratory for Psychological Research, Pázmány Péter Catholic University, Mikszáth tér 1, Budapest, H-1088, Hungary
2 Institute for Methodology of Special Education and Rehabilitation, Eötvös Loránd University Bárczi Gusztáv Faculty of Special Education, Ecseri út 3, Budapest, H-1097, Hungary
3 Department of General Psychology, Pázmány Péter Catholic University, Mikszáth tér 1, Budapest, H-1088, Hungary
4 Department of Medical Psychology, Institute of Behavioural Sciences, Semmelweis University, Nagyvárad tér 4, Budapest, H-1089, Hungary
5 PhD School of Mental Health Sciences, Semmelweis University, Balassa u. 6, Budapest, H-1089, Hungary
Abstract
There are two basic stages of fine motor learning: performance gain might occur during practice (online learning), and improvement might take place without any further practice (offline learning). Offline learning, also called consolidation, has a sleep-dependent stage in terms of both speed and accuracy of the learned movement. Sleep spindle or sigma band characteristics affect motor learning in typically developing individuals. Here we ask whether the earlier found, altered sigma activity in a neurodevelopmental disorder (Williams syndrome, WS) predicts motor learning. TD and WS participants practiced in a sequential finger tapping (FT) task for two days. Although WS participants started out at a lower performance level, TD and WS participants had a comparable amount of online and offline learning in terms of the accuracy of movement. Spectral analysis of WS sleep EEG recordings revealed that motor accuracy improvement is intricately related to WS-specific NREM sleep EEG features in the 8–16 Hz range profiles: higher 11–13.5 Hz z-transformed power is associated with higher offline FT accuracy improvement; and higher oscillatory peak frequencies are associated with lower offline accuracy improvements. These findings indicate a fundamental relationship between sleep spindle (or sigma band) activity and motor learning in WS.
Keywords: Consolidation, Neurophysiology