EEG COORDINATION DYNAMICS: self-organization in the brain

1. The Human Brain and Behavior Laboratory EEG COORDINATION DYNAMICS: self-organization in the brain http://www.ccs.fau.edu/hbbl.html Emmanuelle Tognoli 12/17/2007 Merck – West-Point

2. The Human Brain and Behavior Laboratory IntroductionThe paradigm of EEG in “cognitive neuroscience” http://www.ccs.fau.edu/hbbl.html

3. Grey Walter

4. local areas inter-areal connectivity, circuits

5. The Human Brain and Behavior Laboratory Neuromarkers of social behaviorA dual EEG study http://www.ccs.fau.edu/hbbl.html

6. SUBJECTS: Sixteen subjects (10 males, 6 females, aged between 22 and 41 years, (mean 29 years). Constituted 8 pairs: 4 gender-mixed; 3 male-male; 1 female-female. All right-handed on the basis of self-report. Had normal or corrected-to-normal vision and reported no history of neurological disease. TASK: perform regular continuous finger movements at a comfortable pace during one minute trials. Subjects are instructed to adopt the most comfortable pace, at any time during the trial t=0-20s t=20-40s t=40-60s DUAL-EEG RECORDING: Dual-EEG recorded using two 60-channel EEG caps with Ag-AgCl electrodes (Falk Minow Services, Germany) arranged according to the 10 percent system (midline and rows 1 to 8), with 2 distinct referential montages. Signals directed to a single amplifier (Synamp2, Neuroscan, Texas) analog filtered (Butterworth, bandpass from 0.05 Hz ( -12 dB/octave) to 200 Hz (-24 dB/octave), amplified (gain= 2010) and digitized at 1000 Hz with a 24 bits ADC in the range ±950 microV (vertical resolution of 0.11nV). Recording performed with the respective grounds located at FPz sites and the references at the corresponding linked mastoids. Impedances maintained below 10 kOhms. TRIALS: 36 trials lasting 1 minute. Vision of the other controlled through fast-switching (1.2ms) LCD screen, turning transparent at t=20s and back to opaque at t=40s

8. Space (scalp surface): 2D Frequency: 1D Amplitude: 1D Scott KELSO Fs: 1000 Hz Samples: 16384 Spectral Resolution: 0.06Hz Spatio-spectral patterns 16.384 sec

11. fERS aERD m ERD + = trouble

12. The Human Brain and Behavior Laboratory Assessment:method is sensitive (small change -obscured by other processes- can be detected)cracks-down sources of inter-individual variabilityhas a good construct validity (the measure of mu is a measure of mu, not a measure of mixed processes)differentiates difficultly distinguishable neural activitiesessentially yields information about local areas (see after) http://www.ccs.fau.edu/hbbl.html

14. The Human Brain and Behavior Laboratory Assessment:method is sensitive (small change -obscured by other processes- can be detected)cracks-down sources of inter-individual variabilityhas a good construct validity (the measure of mu is a measure of mu, not a measure of mixed processes)differentiates difficultly distinguishable neural activitiesessentially yields information about local areas (see after) http://www.ccs.fau.edu/hbbl.html

15. f1, f2 avariant m x

16. The Human Brain and Behavior Laboratory Assessment:method is sensitive (small change -obscured by other processes- can be detected)cracks-down sources of inter-individual variabilityhas a good construct validity (the measure of mu is a measure of mu, not a measure of mixed processes)differentiates difficultly distinguishable neural activitiesessentially yields information about local areas (see after) http://www.ccs.fau.edu/hbbl.html

17. The Human Brain and Behavior Laboratory Theory of Coordination Dynamics:Self-organization of oscillatory ensembles http://www.ccs.fau.edu/hbbl.html

18. Christiaan Huygens

19. p/2 p/2 p/2 p p 0 0 p 0 3p/2 3p/2 3p/2 4p/3 0 msec 67 msec 50 msec A C B

20. f = dw - a sinf - 2b sin (2f) + Qxt

21. Walter Freeman “…my evidence in the past 18 years for sustained synchrony (never antiphasic), for spatial phase gradients in intracranial EEGs from high-density arrays,  and for phase cones with phase velocities corresponding to intracortical axonal propagation velocities as evidence for state transitions.”Walter Freeman

22. p/2 p 0 3p/2 Zero-Lag Synchronization Electrical: Spatial summation Chemical: LTP/LTD 0 msec A

23. The Human Brain and Behavior Laboratory Transiently Synchronized Neural Cell Assemblies:Phase Locking in the brain? http://www.ccs.fau.edu/hbbl.html

24. Inphase in scalp EEG?

25. Antiphase in scalp EEG? Indeed by the plenty (too many):

26. Rodriguez et al., 1999 Nature

27. f = dw - a sinf - 2b sin (2f) + Qxt Brief Rare Smaller amplitude broken symmetry 2p p 0

28. Where is the true antiphase? Forward models The same volume conduction effect that emphasizes spurious antiphase synchrony also attenuates real antiphase synchrony.

29. The Human Brain and Behavior Laboratory Forward models of source pairs:states and transitions http://www.ccs.fau.edu/hbbl.html

30. E1=0.95*S1+p*S2 E2=0.95*S2+p*S1 E2: AE2: amplitude at location 1 fE2: frequency at location 1 fE2: phase at location 1 E1: AE1: amplitude at location 1 fE1:frequency at location 1 fE1: phase at location 1 S2: AS2: amplitude at location 1 fS2: frequency at location 1 fS2: phase at location 1 S1: AS1: amplitude at location 1 fS1:frequency at location 1 fS1: phase at location 1

33. Transitions, intermittency, uncoupled areas

35. AMPLITUDE MODULATION

36. Assessment:While the average picture (part I):-discarded critical information (inter-areal coupling)-created intra- and inter-individual variability -occasionally created fictive properties-prevented introduction many variables/steps in protocols (parameter spaces)The continuous method:-yields first deterministic findings of inter-areal synchronization-has temporal resolution at the limit of recording instruments (pharmaco-dynamics)-has maximal consistency-and above all…

37. In general, EEGamplitude IS NOT speaking about corticalsourcestrength