Neural Field Dynamics and the Evolution 2 of the Cerebral Cortex

We describe principles for cortical development which may apply both 5 to the evolution of species, and to the antenatal development of the cortex of indi6 viduals. Our account depends upon the occurrence of synchronous oscillation in the 7 neural field during embryonic development, and the assumption that synchrony is 8 linked to cell survival during apoptosis. This leads to selection of arrays of neurons 9 with ultra-small-world characteristics. The “degree of separation” power law is 10 supplied by the combination of neuron sub-populations with differing exponential 11 axonal tree distributions, and consequently, in the visual cortex, connections emerge 12 in anatomically realistic patterns, with an ante-natal arrangement which projects 13 signals from the surrounding cortex onto each macrocolumn, in a form analogous to 14 the projection of a Euclidean plane onto a Möbius strip. Simulations of signal flow 15 explain cortical responses to moving lines as functions of stimulus velocity, length 16 and orientation. With the introduction of direct visual inputs, under the operation 17 of Hebbian learning, development of mature selective response “tuning” to stimuli 18 “features” then takes place, overwriting the earlier ante-natal configuration. Further 19 assuming similar development principles apply to inter-areal interactions in the 20 developing cortex, a general principle for the evolution of increasingly complicated 21 sensory-motor sequences, at both species-evolution and individual time-scales, is 22 implicit. 23 J.J. Wright (!) Faculty of Medicine, Department of Psychological Medicine, University of Auckland, Auckland, New Zealand AQ1 P.D. Bourke iVEC@UWA, University of Western Australia, Perth, WA, Australia S. Coombes et al. (eds.), Neural Fields, DOI 10.1007/978-3-642-54593-1__18, © Springer-Verlag Berlin Heidelberg 2014 UN CO RR EC TE D PR OO F J.J. Wright and P.D. Bourke 18.