Investigation of both power and coherence differences of brain lobes in two mathematical thinking tasks

The purpose of this study is to investigate in terms of power and coherence the differences between two mathematical tasks, number addition and number comparison. Firstly, the time-frequency maps of the EEG signals are computed and averaged over the different regions, frequency bands and subjects. Then the linear coherence of the EEG channels is estimated among the electrodes of the same region. The results are compared to resting case EEG and are found in accordance with previous studies. The power and coherence are combined in order to investigate whether the power increase or decrease within the task is correlated with coherence alterations in the brain regions. Also there is an attempt to compare the two mathematical tasks in terms of functionality, as it is reflected in power and synchronization measures of the EEG.