Sympathy of the Brain - Emmanuelle Tognoli, Shanghai, ECNU
1. Emmanuelle Tognoli - Center for Complex Systems & Brain Sciences -
Florida Atlantic University
Unknownartist,BurningManFestival,2005
Sympathy of the brains
2. Theory
1. Huygens
2. Coordination Dynamics
5. Metastability
6. Multiscale
7. Multisystem
Experiments
Dyadic social coordination .8
Phi neuromarker .10
Social neuromarkers .11
Paths not taken .12
Synced transition .13
3. Relative phase
9. 4D Colorimetric mapping
Analysis
HKB .4
Models
3. Huygens, Sympathy of the Clocks
Dutch Royal Marine Scientist, 17th century
Sick day in bed
Has just received two pendulum clocks
Suspended from a wooden beam
Used to find longitude at sea
Paired for surrogacy during clean-up on ships
Oscillate antiphase
Theory of weakly coupled oscillators
Social brains: oscillators + weak coupling
→ “Sympathy” of the Brains?
Tognoli, 2008
4. Relative Phase
time
x=0
x=1
x=1
x=0 x=0
x=-1
x=-1
x=0
x=0
x=1
x
.
.
.
. .
Phase
1 oscillator
Relative phase
2 oscillators
(Coordination Dynamics)
E.g.
canonical
periodic
signal: sine
Position on
the cycle:
phase
Mapped on
the unit
circle, 𝑥, 𝑥
Trajectory
of relative
phase
reveals
dynamics of
(1:1)
coordinatio
n
5. Equations of Coordination Dynamics
Oscillators: non-linear, self sustained
Initially modelled finger movement
Intrinsic frequency
Coupling: without (top) or with (bottom)
broken symmetry
Attractors (phase locking) or attracting
tendencies/remnants (dwell)
Key attributes: Coupling strength and
symmetry breaking
f = dw - a sinf - 2b sin (2f) + Qxt
8. Multiscale
Kelso, Dumas & Tognoli,
Neural Networks, 2013
30 yrs of research at
Center for Complex
Systems and Brain
Sciences:
Same phenomena,
same laws observed
at all scales.
9. Dyadic social coordination paradigm
t=20-40st=0-20s t=40-60s
A paradigm for simultaneous
perception~action in 2 people.
Weak coupling between sensory (observed
action) and motor system (motor “intention”)
Collective
Behaviors:
Uncoordinated
(top)
Synchronized
(bottom)
Transiently
synchronized
10. 4D colorimetric mapping
v
t
x
y
space
wave amplitude
time
x
y
abscissa
“wave length”
(colorimetric model)
ordinates
EEG dynamics carries 4D, topography
(2D), amplitude and time.
Overwhelms visualization ceiling at 3D
Trick of color Gestalt: similarity in
colors familiar to human brain.
4D spatio-temporal
or spatio-spectral
representations of
EEG data
11. Phi neuromarker
With colorimetric mapping, we
discovered a new peak (red) in the
well-known 10Hz (“alpha”)
frequency band of interacting
people’s EEG: phi complex
Spectral power lateralization graph
(suppresses large peaks with bilateral power)
revealed 2 subcomponents f1 and f2
f1 increases during independent behavior
f2 increases during coordinated behavior
13. Paths not taken: sympathy of between-brain oscillations
Steady states of the movement
(e.g. ~2Hz)
Risk of induction in the EEG
wiring
Coupling of identical rhythms,
e.g. n with n
Individual differences an obstacle
No evidence of co-activated
“microstates” (see after)
n, small amplitude, 9Hz
n, large amplitude,
11Hz
n, broad band, 9Hz
14. Synced transitions
Microstates from top and
bottom subjects
uncorrelated.
But microstate switch
coordinated between
subjects during behavioral
transitions (dashed line).
We have shown that EEG
transitions result from
spatiotemporal metastability
(Tognoli & Kelso, 2014, Neuron).
Behavior is the key
organizing factor.
15. Summary
Interacting brains, unlike pendula: complex systems
We have not identified unambiguous evidence of “sympathy”
between brains:
- interindividual variability: broken symmetry
- weak coupling
We have found synced transitions as a coordination
mechanism between brains
Suggest that coordination between brains, just like within-
brain and in behavior, is metastable.
16. Acknowledgments
Scott Kelso
Julien Lagarde
Gonzalo de Guzman
Guillaume Dumas
Daniela Benites
Mengsen Zhang
Roxana Stefanescu
Rodrigo Calderon
Benjamin Suutari
Seth Weisberg
Armin Fuchs
Slava Murzin
William Mc Lean
