Julius 9-en hetfon 14 orakor a KFKI RMKI Tancstermeben (III-as epulet)
szimnariumi eloadas lesz:
********************************************************
Viktor Jirsa
Center for Complex Systems & Brain Sciences
Florida Atlantic University
http://www.ccs.fau.edu/%7Ejirsa/
**************************************************************************
Neural field dynamics as a window for understanding the EEG and MEG during
motor coordination
*************************************************************************
Minden erdelkodot szerettel varunk.
(erdi peter)
++++++++++++++++++++++++++++++++++++++++++++++++++
Az eloadas kivonata:
Dynamic systems defined on the scale of neural ensembles are well-suited
to model the spatiotemporal dynamics of neural fields on the cortical
sheet. These represent the current flow perpendicular to the cortex and
generate the electric potentials on the surface of the skull and the
magnetic fields outside the skull measured by electroencephalography (EEG)
and magnetoencephalography (MEG), respectively. We wish to connect
spatiotemporal neural field dynamics (Jirsa-Haken, Phys.Rev.Let. 1996) to
motor behavior and simultaneous brain activity and take the following
approach: 1. We develop a methodological framework, which defines the
activity of the neural field on a sphere in three dimensions. Using
Magnetic Resonance Imaging (MRI) we map the neural field dynamics from the
sphere onto the folded cortical surface and calculate the
three-dimensional forward solutions of EEG and MEG. Non-trivial mappings
between the multiple levels of observation are obtained which would not be
predicted by inverse solution techniques. 2. Recent results mapping
large-scale brain dynamics (EEG, MEG) onto behavioral motor patterns
(Fuchs, Jirsa, Kelso, Neuroimage 2000) provide an entry point to the
causal brain-behavior relation which we use to
define a motor and sensorimotor loop between neural fields and behavioral
data. For the case of bimanual coordination, we establish the neural field
dynamics including short-and long range connections of neural ensembles.
We make predictions of global features of brain dynamics during
coordination tasks and test these against experimental MEG results. A key
feature of our approach is that phenomenological laws at the behavioral
level can be connected to a field theoretical description of cortical
dynamics (see also Jirsa, Fuchs, Kelso, Neural Comp. 1998).
