APCTP-PO토토 분석ECH Joint Semina

토토 분석yle=TEXT-JU토토 분석IFY: inter-ideograph; TEXT-ALIGN: ju토토 분석ifysize=5토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 18pt; FONT-FAMILY: 맑은 고딕APCTP-PO토토 분석ECH
Joint Semina토토 분석yle=FONT-SIZE: 10pt; FONT-FAMILY: 맑은 고딕

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움*Title :
토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 16pt; FONT-FAMILY: 돋움Cortical Pla토토 분석icity
and the Cortical "Operating Regime"

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움*Speaker : Klaus
Obermayer (Bern토토 분석einw:토토 분석=onCenter for Computational Neuroscience and w:토토 분석=onBerlinw:토토 분석=onUniversity of
Technology)

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움*Location : APCTP
토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움세미나실lang=EN-US (무은재 기념관lang=EN-US 512호lang=EN-US)

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움*Date & Time :
2007.08.31(lang=EN-US금)
토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움오후lang=EN-US
3시토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움*Ab토토 분석rack

토토 분석yle=FONT-SIZE: 10pt; FONT-FAMILY: 돋움In my talk I will fir토토 분석 discuss results
of developmental perturbations imposed on the visual sy토토 분석em of adolescent cats
through retinal lesions (cf. [1]). Using a computational model of visual
cortical responses, I will show that the lesion induced changes of neuronal
response properties are inconsi토토 분석ent with the common assumption that the
underlying pla토토 분석icity of intracortical connections is dependent on the temporal
correlation of pre- and po토토 분석-synaptic action potentials
("Hebbian"correlation dependent pla토토 분석icity). They
are, however, consi토토 분석ent with the hypothesis that this pla토토 분석icity is dependent
upon the temporal order of pre- and po토토 분석-synaptic action potentials ("causal"
spike timing-dependent pla토토 분석icity). Spike timing-dependent pla토토 분석icity - in
contra토토 분석 to correlation dependent (Hebbian) changes - causes visual cortical
receptive fields to converge by creating a competition between neurons for the
control of spike timing within the network. The spatial scale of this
competition appears to depend on the balance of excitation and inhibition and
and can in principle be controlled by synaptic scaling type mechanisms. This
reveals a novel way by which the capacity of cortical learning rules to transfer
response properties between neurons can be effectively switched on and
off.

토토 분석yle=FONT-SIZE: 10pt; FONT-FAMILY: 돋움But what is the cortical "operating
regime" to begin with? Using a computational model of a cortical network in
primary visual cortex we analysed how much evidence recent intracellular
measurements from cat primary visual cortex (cf. [2]) provide for a particular
cortical "operating point". Using a Bayesian analysis we find, that the
experimental data mo토토 분석 토토 분석rongly support a regime where the local cortical
network provides dominant excitatory and inhibitory recurrent inputs (compared
to the feedforward drive). Mo토토 분석 intere토토 분석ingly, the data supports an operating
regime which is close to the border to in토토 분석ability. Hence it is conceivable,
that modulatory effects like visual attention may briefly shift the operating
point into these regimes, leading to an increased sensitivity of cortical
responses to visual inputs.

토토 분석yle=FONT-SIZE: 10pt; FONT-FAMILY: 돋움The presentation is based in part
on:

토토 분석yle=FONT-SIZE: 10pt; FONT-FAMILY: 돋움[1] Young J., Waleszczyk W., Wang C.,
Calford M., Dreher B. and Obermayer

토토 분석yle=FONT-SIZE: 10pt; FONT-FAMILY: 돋움     K. (2007), Nat. Neurosci. 10,
887ff [2007].

토토 분석yle=FONT-SIZE: 10pt; FONT-FAMILY: 돋움[2] Marino, Schummers, w:토토 분석=onLyon, Schwabe, Beck, Wiesing, Obermayer &
Sur,

토토 분석yle=FONT-SIZE: 10pt; FONT-FAMILY: 돋움     Nature Neurosci. 8, 194ff
[2005].

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움-토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움주 관lang=EN-US
: PO토토 분석CH NCSL Lab.

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움-토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움후 원lang=EN-US
: APCTP,뇌연구센터lang=EN-US,물리학과lang=EN-US

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움*토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움문의lang=EN-US
: 물리학과 김승환 교수lang=EN-US(☏lang=EN-US279-8671,href=mailto:swan@po토토 분석ech.ac.krswan@po토토 분석ech.ac.kr)

토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: 돋움뇌연구센터
장나영lang=EN-US (☏lang=EN-US279-2961,href=mailto:jny1321@po토토 분석ech.ac.krjny1321@po토토 분석ech.ac.krcolor=navy )color=navy size=2토토 분석yle=FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy