Transcript the file

Role of feed forward and recurrent inhibition and excitation in the
emergence of winner take all (WTA) behavior in a neuromorphic chip
Massimiliano Versace & Elisabetta Chicca
• WTA is a desirable properties in neural circuits that need to perform a ‘choice’, or code compression, from
an input layer to an output (or coding) layer
• Target of the study: study WTA behavior in the IFSLWTA (Integrate-and-fire-stop-learning-winner-take-all)
chip.
5 EXPERIMENTS
(1)
(2)
…
(3)
…
BASELINE
FEED FORWARD INHIBITION
(4)
(5)
…
FEED FORWARD AND
FEED BACK INHIBITION
…
FEED BACK INHIBITION
Legend
…
FEED FORWARD,FEED BACK INHIBITION
AND RECURRENT EXCITATION
Excitatory
cell
Inhibitory
connection
Inhibitory
cell
Excitatory
connection
External
stimulation
Recurrent
excitatation
Results
BASELINE
winner
FEED FORWARD AND
FEED BACK INHIBITION
WITH RECURRENT EXCITATION
This preliminary study explores a subset of excitatory and inhibitory parameters in the
IFSLWTA chip that allows the emergence of WTA behavior through competitive on-center
(excitatory)/off-surround (inhibitory) interactions. THEY EXIST!!
WTA is a useful property: code compression,
or a ‘choice’ among excitatory neurons,
can be used to learn compressed representations.
For example: ocular dominance columns in visual cortex