Higher Brain
Functions The
way by which
perceptions,
memories,
intentions, etc.,
are represented in
the nervous activity
of the brain is not
known. The main
effort of this
research is to
reveal these
representations and
understand the
neuronal mechanism
which generates
them. This is a
combined effort
including recording
the activities of
several nerve cells
in parallel from
appropriate places
in the brain of
behaving monkeys,
devising new
mathematical methods
for analyzing the
data, and verifying
the theory by
constructing (by way
of simulations)
neural networks
which mimic the
postulated brain
processes.
So far we have
discovered that the
prevailing view
about coding by
enhanced neural
activity is only
part of the truth.
The exact timing of
nerve cell activity
contains much of the
information about
what is happening in
the brain. This
timing can be "read"
by neurons due to
their sensitivity to
synchronized
activation. This
same property also
serves as the basic
mechanism by which
exact timing is
generated. A
neural-network known
as synfire chain can
both read and
generate such well
timed activities.
The experimental
results supported
the synfire
hypothesis and
extended it by
suggesting that
activity is
reverberating in
such synfire modes.
We assume that
reverberating
synfire chains in
different brain
locations can
resonate with each
other, thereby
generating a unified
"mental" experience.
Key Words:
cortex; neural
networks; higher
brain functions
Other
Investigators:
I. Asher, B.Sc.; Y.
Aviel, B.Sc.; L.
Basul, B.Sc.; Y. Ben
Shaul, M.Sc.; F.
Fahum, B.Sc.; E.
Fink B.Sc.; V.
Litvak B.Sc.; Dr. Z.
Nadasdi, Ph.D.; S.
Pachornic, M.Sc.; V.
Sharkansky, B.Sc.;
R. Shem Tov B.Sc.;
E. Stark B.Sc.; T.
Shmiel, M.Sc.; L.
Avitan, B.Sc.; K.
Erez, M.Sc.; S.
Gruen, Ph.D.; M.
Shemesh, M.D.; R.
Sosnik, Ph.D.
Collaborating
Investigators:
Prof. A. Aertsen,
Freiburg; Dr. H.
Bergman; Prof. T.
Flash, Mathematics –
Weizmann; Prof. G.L.
Gerstein,
Philadelphia; Prof.
H. Gutfreund,
Physics; Prof. D.
Horn, Physics – Tel
Aviv; Prof. D.
Lehman, Computer
Science; Prof. H.
Sompolinsky,
Physics; Prof. M.
Teich, Mathematics –
Bar Ilan; Prof. N.
Tishby, Computer
Science; Prof. E.
Vaadia; Dr. M.
Hermmann, Guetingen,
Germany; Prof. R.
Geisel, Guetingen,
Germany.
Abeles M. and Gat I.
Detecting precise
firing sequences in
experimental data.
J. Neurosci.
Methods. 107:141-154
(2001).
Ben-Shaul Y.,
Bergman H., Ritov Y.
and Abeles M. Trial
to trial variability
in either stimulus
or action causes
apparent correlation
and synchrony in
neuronal activity.
J. Neurosci.
Methods. 111:99-110
(2001).
Aviel Y., Pavlov E.,
Abeles M., and Horn
D. Synfire chain in
a balanced network.
Neurocomp.
44:285-292 (2002).
Ben-Shaul Y., Stark
E., Asher I., Drori
R., Nadasdy Z., and
Abeles M. Dynamical
organization of
directional tuning
in the primate
premotor and primary
motor cortex. J.
Neurophysiol.,
89:1136-1142 (2003).
Aviel Y. Mehring C.,
Abeles M., and Horn
D. On embedding
synfire chains in a
balanced network.
Neural Comp.
15:1321-1340 (2003).
Litvak V.,
Sompolinsky H.,
Segev I., and Abeles
M. On the
transmission of rate
code in long
feed-forward
networks with
Excitatory-Inhibitory
balance. J. Neurosci.
23:3006-3015 (2003).
Ben-Shaul Y., Drori
R., Asher I., Stark
E., Nadasdy Z., and
Abeles M. Neuronal
activity in motor
cortical areas
reflect the
sequential context
of movement. J.
Neurophys.
91:1748-1762 (2004).
Aviel Y., Horn D.
and Abeles M. Doubly
balanced networks of
spiking neurons: A
memory model with
high capacity.
NIPS03
Aviel Y., Horn D.
and Abeles M. Memory
Capacity of Balanced
networks, Neural
Comp., 2004,
accepted.
Hayon G., Abeles M.,
Lehmann D. Modeling
compositionality by
dynamic binding of
synfire chains. J.
Comp. Neurosci. In
press
Hayon G., Abeles M.,
Lehmann D. A model
for representing the
dynamics of a system
of synfire chains.
J. Comp. Neurosci.
accepted.
