Low frequency phase synchronisation analysis of MEG recordings from children with ADHD and controls using single channel ICA

It has been suggested that the human brain is intrinsically organised into dynamic, anti-correlated functional networks. This paper presents a study on the so-called default mode network - which is active when the brain is apparently at rest - and on brain activity related to a given task. This work involves the analysis of low frequency magnetoencephalographic recordings of children with Attention Deficit Hyperactivity Disorder (ADHD) and controls performing both attentional as well as perceptual tasks. Single channel independent component analysis is used to isolate low frequency brain signals within the data in the presence of higher frequency brain activity and artifacts. Phase synchrony analysis is then carried out between the components of channels of interest to quantify any interaction between distant brain regions within the default-mode network. Preliminary results show variations in the phase locking between ADHD and controls, and indicate a corresponding change in phase synchrony between the corresponding brain regions at periods of rest and when tasks are being performed.