Modelization of the brain

Since some time I am interested in modelling the brain through some self-organized critical model. One first attempt was a model developped with Enrique Miranda who works now in Argentina as described in the paper published in Physica A, Vol. 175, 339-344 (1991)

Photo

Recently we made a more successful model with Lucilla de Arcangelis and Carla Perrone in which neurons reinforce their synapses each time they fire while the not used synapses weaken constantly. If a synapse is too weak it disappears (= is "pruned"). Note that this rule does not correspond to Hebb's rule. We measure the time dependent electrical signal of a network made out of such neurons and excited always at one given input. Interestingly we obtain a signal which has a power spectrum following a power law with an exponent 0.8 which fully agrees with electroencephalograms and other neural signals like the pace maker of the heart or the human gait. In the figure you see above an EEG and below two of out time series. We submitted these results in a paper to Physical Review Letters.

Photo