Digital Signal Processing and System Theory

Talk Muthuraman Muthuraman


mm
Oscillations in the Brain

Date: 03.06.2013, 17:15 h - 18:15 h
Room: Aquarium

Dr. -Ing. Muthuraman Muthuraman
CAU, Kiel, Germany,
Department of Neurology



Details



In the brain when a large number of neurons are active and firing synchronously it induces large scale macroscopic oscillations. These oscillations can be recorded on the scalp using electroencephalography (EEG) and magnetoencephalography (MEG). The oscillatory activity are observed at different levels (i.e. cellular or neuronal) using different brain imaging techniques which plays a vital role in understanding the information processing in the brain. The rhythmic activity frequency bands are subdivided into delta (1-4 Hz), theta (4-7 Hz), alpha (7-13 Hz), beta (13-30 Hz) and gamma (30-100+ Hz). All these oscillations are generated during different processes and at different regions in the brain. Getting insights on these oscillations can help us in preventing and treating certain brain diseases. In this talk, the analysis of these frequency oscillations is presented. The method used to characterize them is the power spectrum which gives information about the frequency and amplitude. The coupling between two signals can be extracted using coherence, and the dynamics of the power and coherence is obtained using time frequency analysis. A beamforming approach which applies a spatial filter is used to identify the regions in the brain responsible for these oscillations. The network of interaction between these source regions give us more insights about their information flows between the regions which are responsible for certain processes in the brain.