Adaptive models of cortex cooperating with other brain parts

Cortex is considered as the main brain functional block in which the mentation and rational operations are realized. Various cortex models are known, however they usually do not respect the brain functional and also structural adaptivity. Before already many years Farlay and Clark (1954) have presented a model of  artificial neuronal network (ANN) which had consisted of  one considerably large functional block – they called it complex consisting of 128  randomly connected elements (neuroids, neurons) which were imaginarily divided into four sectors: input O1 and O2 and output O+, O-. The signal generator (modeling here the operation of thalamus) sends impulses alternatively to O1 or O2 with the aim of self-organizing stimulating solely O+ at O1 activation and, vice versa, solely O- at O2 activation. The system had not converged to expected state unless two other parts were added, i.e.,

1) the discriminatory or analytical unit (modeling the limbic system) designed to monitor the states of organization of the complex  and to send the relevant information into the signal generator and 

2) the formator (modeling modulatory humoroergic brain-stem nuclei in control of vigilance, NON-REM synchronous sleep and REM-paradoxical sleep).

According to actual need, the formator changes the complex elements threshold and sends stimulating signals (Gaussian noise) into the complex. 

In such manner completed Farley and Clark model works well, but without respect to its progressivity, it was almost forgotten, probably because of its limitation to relatively small and one-layer structures of complex.

We have tried to extend this old adaptive model more close to real cortex, taking into account also its layered structure.

We estimate, that disorders of the formators operation give rise to quasistable behavior of such models, similar to such brain pathological states like epilepsy, psychosis, pavor nocturnus or somnambulism and other dissociated states, e.g. anxious attechment, hidden dynamic psychotrauma spent.during childhood etc.

In mammals including humans, formators were already found and are now classified into eutopic (truncus cerebri) and ectopic (Brodmanns´cortical areas), parts, either being subdivided into physiological (ascendent reticular activation system, nuclei raphe and nucleus suprachiasmaticus, nuclei pontis Varoli) and pathological kinds (epileptic foci).

References

Farley B.G., Clark W.A.: Simulation of self-organizing system by digital computer., Transactions IRE, vol.PGIT-4, 1954, pp:78-84,

Faber J.,  Vladyka V:  Nocturnal sleep stereo-EEG and polygraphy in epileptics. Acta. Univ. Carol. Med. Monogr .CVIII Prague, 1984,

Kolda T, Faber J, Svoboda P, Dvořák M: A model of arteficial beuronal  networks designed.according  the natural neuronal brain structures, Neural Networks World,  2004, pp. 133-246, 

Novák M. et al.:The artificial neuronal networks (in Czech: Teorie a aplikace umělých neuronových sítí),  CH Beck, Prague, 1998, pp. 382..