Infra-slow Oscillations During Sleep

Inclusion Criteria for all participants: * Willingness to participate and written informed consent * Aged 20 to 40 years at the time of screening * Body mass index (BMI) ≤ 30 Additional inclusion criteria for subjects with RLS/PLMS: * Either diagnosis of RLS and current IRLS score ≥ 15. * Or frequent periodic leg movements during sleep Exclusion criteria for all participants: * Pregnancy or breast feeding at the time of screening * Sleep related breathing disorders * Current psychiatric disorders * Current chronic treatment that may affect sleep. * Any significant neurological disorder or other medical disease that may affect sleep. * Any unstable medical condition. Additional exclusion criteria for participants with RLS/PLMS: * Current intake of dopaminergic drugs * Current intake of other RLS relevant medication * Intake of hypnotics * Other significant sleep disorder except symptoms potentially related to RLS Additional exclusion criteria for healthy participants: * Any pharmacological treatment that may affect sleep and/or sleep related movement disorders * Any clinically significant sleep disorders