?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Dynamics+of+the+brain+at+global+and+microscopic+scales%3A+Neural+networks+and+the+EEG&rft.creator=Wright%2C+J.J.&rft.creator=Liley%2C+D.T.L&rft.subject=Brain+Imaging&rft.subject=Computational+Neuroscience&rft.subject=Neural+Modelling&rft.description=There+is+some+complementarity+of+models+for+the+origin+of+the+electroencephalogram+(EEG)+and+neural+network+models+for+information+storage+in+brainlike+systems.+From+the+EEG+models+of+Freeman%2C+of+Nunez%2C+and+of+the+authors'+group+we+argue+that+the+wavelike+processes+revealed+in+the+EEG+exhibit+linear+and+near-equilibrium+dynamics+at+macroscopic+scale%2C+despite+extremely+nonlinear+-+probably+chaotic+-+dynamics+at+microscopic+scale.+Simulations+of+cortical+neuronal+interactions+at+global+and+microscopic+scales+are+then+presented.+The+simulations+depend+on+anatomical+and+physiological+estimates+of+synaptic+densities%2C+coupling+symmetries%2C+synaptic+gain%2C+dendritic+time+constants%2C+and+axonal+delays.+It+is+shown+that+the+frequency+content%2C+wave+velocities%2C+frequency%2Fwavenumber+spectra+and+response+to+cortical+activation+of+the+electrocorticogram+(ECoG)+can+be+reproduced+by+a+%22lumped%22+simulation+treating+small+cortical+areas+as+single-function+units.+The+corresponding+cellular+neural+network+simulation+has+properties+that+include+those+of+attractor+neural+networks+proposed+by+Amit+and+by+Parisi.+Within+the+simulations+at+both+scales%2C+sharp+transitions+occur+between+low+and+high+cell+firing+rates.+These+transitions+may+form+a+basis+for+neural+interactions+across+scale.+To+maintain+overall+cortical+dynamics+in+the+normal+low+firing-rate+range%2C+interactions+between+the+cortex+and+the+subcortical+systems+are+required+to+prevent+runaway+global+excitation.+Thus%2C+the+interaction+of+cortex+and+subcortex+via+corticostriatal+and+related+pathways+may+partly+regulate+global+dynamics+by+a+principle+analogous+to+adiabatic+control+of+artificial+neural+networks.&rft.date=1996&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=text%2Fhtml&rft.identifier=http%3A%2F%2Fcogprints.org%2F47%2F1%2Findex.html&rft.identifier=++Wright%2C+J.J.+and+Liley%2C+D.T.L++(1996)+Dynamics+of+the+brain+at+global+and+microscopic+scales%3A+Neural+networks+and+the+EEG.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F47%2F