Sensory and Motor Systems
Author: Agustín Solano | email: asolano@bioingenieria.edu.ar
Agustín Solano 1°, Gonzalo Lerner 1°, Pedro Caffaro 1°, Luis Alberto Riquelme 1°, Daniel Perez-Chada 2°, Valeria Della-Maggiore 1°
1° CONICET-Universidad de Buenos Aires, IFIBIO Houssay, Buenos Aires, Argentina
2° Internal Medicine, Pulmonary and Sleep Service, Austral Univ. Hosp., Pilar, Argentina
Strong evidence suggests that sleep benefits declarative memories (DM). However, its contribution to motor learning is controversial. Recently, we showed that learning a motor adaptation (MA) task shortly before sleep enhances the delta power and the coupling between spindles and slow oscillations (SO), similarly to what is observed in DM. Here, we tested the hypothesis that the beneficial effect of sleep in MA depends on its overlap with the consolidation window. First, we tracked MA memory retention through a 24h window. We found that it decayed initially and stabilized at 6h post training, and remained constant overnight (p<0.001), suggesting that sleep does not benefit MA if the time proximity between learning and sleep is not controlled. To control the interval between learning and sleep we then tracked the time course of MA memory consolidation using an anterograde interference protocol. We found that release from interference started about 6h post learning (p<0.001), implying that MA consolidates within such a time window. Finally, we trained two groups of subjects so that sleep occurred outside (~14h; group T-14h) or inside (~10min; group T-10min) the consolidation window, and recorded EEG overnight. We found that T-10min retained 30% more than T-14h (p<0.05). This sleep benefit was accompanied by an increment in the spindle-SO coupling and delta band power over the brain hemisphere contralateral to the trained hand (p<0.05), supporting our hypothesis.