For more details see:

Kelso J.A.S., Bressler S.L., Buchanan S., DeGuzman G.C., Ding M., Fuchs A., Holroyd T.: `Cooperative and critical phenomena in the human brain revealed by multiple SQUIDs', in: Measuring Chaos in the Human Brain, D. Duke & W. Pritchard, eds., World Scientific, Singapore (1991)

Kelso J.A.S., Bressler S.L., Buchanan S., DeGuzman G.C., Ding M., Fuchs A., Holroyd T.: `Phase transition in human brain and behavior', Phys. Lett. A 169: 134-144 (1992)

Fuchs A., Kelso J.A.S., Haken H.: `Phase Transitions in the Human Brain: Spatial Mode Dynamics', Int. J. Bifurc. Chaos, 2: 917-939 (1992)

Jirsa V.K., Friedrich R., Haken H., Kelso J.A.S.: `A theoretical model of phase transitions in the human brain', Biol. Cybern. 71: 27-35 (1994)

Jirsa V.K., Friedrich R., Haken, HL Reconstruction of the spatiotemporal dynamics of a human magnetoencephalogram, Physica D 89, 100-122 (1995)

This MPEG-movie shows the spatiotemporal dynamics of neural magnetic activity recorded during a perceptual-motor coordination task. A subject is exposed to a rhythmic stimulus and instructed to press a button in the middle of two consecutive tones i.e. to syncopate with the stimulus. After every ten tones the time interval between the tones is decreased. At a certain frequency (around 1.75 Hz) the subject is no longer able to keep the syncopation pattern and switches spontaneously to a coordination pattern for which the stimulus and the response are synchronized. During this task the subject's MEG was recorded over the left temporal parietal region using a 37-channel BTI SQuID device. The signals from about 30 runs are averaged.

Experimental Data and Simulation (mpeg 5194K)

The analysis and modeling performed for this experiment are summarized in the movie. The image in the upper left shows the spatiotemporal data interpolated in space. The analysis shows that the spatiotemporal dynamics can be reconstructed by a superposition of 3 spatial non-orthogonal patterns and their corresponding amplitudes. The image in the upper middle shows the pattern reconstructed from these 3 modes. The upper red and yellow time series and the upper green time series represent the corresponding amplitudes. Vertical red lines mark the points in time where the frequency of the stimulus was changed; we refer to a region with a constant stimulus frequency as a plateau. On the first two plateaus the subject syncopates with the stimulus whereas on the last two plateaus the movement and the stimulus are synchronized (the plateaus where the transition takes place are not shown here). The dynamics of the 3 spatial modes above was modeled using coupled nonlinear oscillators. The time series from this model are the lower of the yellow and red and the lower of the green curves. Notice that they match quite well the experimental data but are less noisy. The image in the upper right corner is the reconstruction of the entire spatiotemporal dynamics from the model i.e. the superposition of the time series multiplied with the corresponding spatial patterns.