Frequency diversity of posterior oscillatory activity in human revealed by spatial filtered MEG.

摘要: The posterior EEG alpha rhythm is a distinctive feature of the normal brain in waking state, consisting oscillations within 8-15 Hz frequency range over cortical regions. This activity appears resting, eyes-closed condition and typically suppressed by eyes-opening. Other physiological rhythms band, particular Rolandic mu rhythm, are proposed to include fast component beta range. In this study we used spatial filtering techniques permutation analysis explore source-power changes related magnetoencephalography (MEG) counterpart rhythm. We also aimed at determining possible implication components outside reactivity eye closure. recorded resting using whole-head MEG system fifteen subjects. applied an eyes-open/eyes-closed paradigm. A significant increase after eyes closing, representing was observed bilaterally occipital parietal cortex, including calcarine fissure parieto-occipital sulcus. found (15-30 Hz) low gamma (30-60 oscillations. classical had similar topographic distribution regions, although with different strength extension. These features were highest for synchronized oscillations, intermediate beta, lowest activity. results suggest that, like dominant may be impure, mixture predominant high-frequency components.