Öffentliche Verteidigung im Rahmen der Promotion
Herr Dipl.-Inf. Michael Teichmann
Fakultät für Informatik
Professur Künstliche Intellligenz
"A plastic multilayer network of the early visual system inspired by the neocortical circuit"
11:00 Uhr, Straße der Nationen 62, Böttcher-Bau, 1/204 (neu: A10.204)
We propose a computational model of the visual areas V1 and V2, implementing a rich connectivity inspired by the neocortical circuit. We combined the three most important cortical plasticity mechanisms. 1) Hebbian synaptic plasticity to learn the synapse strengths of excitatory and inhibitory neurons, including trace learning to learn invariant representations. 2) Intrinsic plasticity to regulate the neurons response properties and stabilize the learning in deeper network layers. 3) Structural plasticity to modify the connections during network training and to overcome the bias for the learnings from the initial definitions.
Among others, we show that our model neurons learn comparable receptive fields to cortical ones. We verify the invariant object recognition performance of the model. We further show that the developed weight strengths and connection probabilities depend on the correlations between the neurons. We link the connection probabilities of the inhibitory connections to the underlying plasticity mechanisms and explain why inhibitory connections appear unspecific.
The proposed model is more detailed than previous approaches. It can reproduce neuroscientific findings and fulfills the purpose of the visual system, invariant object recognition.