?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Biology+of+Brain+waves%3A+natural+history+and+evolution+of+an+information-rich+sign+of+activity.&rft.creator=Bullock%2C+Professor+of+Neuroscience+Theodore+Holmes&rft.subject=Neurophysiology&rft.description=Using+%22brain+waves%22+and+%22EEG%22+broadly+for+ongoing+electrical+activity+and+stimulus-+or+event-related+activity+of+organized+masses+of+neural+tissue+as+seen+by+wideband+amplifiers+and+macro-%2C+micro-+or+semi-microelectrodes+within+or+in+electrical+contact+with+the+central+nervous+system%2C+I+consider+the+character+of+these+signs+in+animals+of+many+phyla%2C+by+various+descriptors%2C+emphasizing+local+field+potentials%2C+pregnant+questions+and+research+opportunities.%0A%09We+still+have+inadequate+or+hardly+tested+ideas+of+why+most+invertebrates%2C+large+and+small%2C+have+inconspicuous+slow+waves+(%3C50+Hz)+and+conspicuous+spikes.+They+can%2C+however%2C+show+slow+waves+under+certain+conditions%2C+somewhat+reminiscent+of+spinal+cord%2C+cerebellum+or+retina.+%0A%09We+have+even+less+tested+explanations+of+the+strong+similarity+of+all+vertebrates%3A+fish%2C+amphibians%2C+reptiles%2C+birds+and+mammals%2C+large+and+small+-+with+respect+to+the+power+spectrum+of+conspicuous+slow+and+inconspicuous+spikes+(until+hunted+by+microelectrodes).+Amplitude+is+the+only+obvious+difference+among+vertebrate+classes%2C+mammals+being+highest.+This+may+come+from+an+evolution+of+the+prevalence+of+synchrony%2C+attrubutable%2C+if+true%2C+to+a+generally+higher+coherence+between+pairs+of+sites+in+reptiles%2C+birds+and+especially+mammals.%0A%09The+strong+similarity+in+the+power+spectrum%2C+among+taxa+with+and+without+a+cortex%2C+is+only+one+of+several+reasons+to+believe+that+we+have+not+found+the+most+relevant+measures+to+reveal+the+real+structure+of+the+time+series%2C+in+space+and+time.+Fine+structure+in+the+millimeter+and+fractional+second+domains%2C+in+the+seemingly+stochastic%2C+wideband+component+of+activity+is+probably+widespread+and+greater+in+mammals+than+in+fish.%0A%09It+has+properties+that+are+not+obvious%2C+such+as+nonlinear+quadratic+phase+couplings+and+pseudo-periodicities%2C+locally+and+episodically.+Wavelet+analysis%2C+independent+component+analysis+and+other+tools+that+might+reveal+nonrhythmic+fine+structure+have+not+yet+been+applied+to+evolutionary+studies.%0A%09A+new+tool%2C+the+Period-Specific-Average+(PSA)+can+show+real+rhythms+even+when+the+power+spectrum+does+not+and+shows+absence+of+rhythms+at+some+frequencies+where+the+power+spectrum+peaks+showing+Fourier+components+of+irregular+transients.+The+PSA+shows+that+most+of+the+spectrum+most+of+the+time+in+most+human+cortex+is+without+rhythms.+Special+conditions+bring+out+episodes+of+delta%2C+theta%2C+alpha%2C+beta+and+gamma+waves+and+their+subtypes%2C+usually+only+one+or+two+at+once%2C+while+most+of+the+energy+is+wideband+and+seemingly+stochastic.+Between+episodes+of+one+or+two+rhythms+there+are+major+periods+of+time+in+normal+human+life+without+any+significant+rhythm+in+cortical+surface+(subdural)+and+depth+electrodes.+In+spite+of+many+kinds+of+sophisticated+analyses%2C+gross+mappings%2C+and+models%2C+with+our+present+understanding%2C+we+cannot+yet+anticipate+the+character+of+scalp+or+subdural+surface+or+macroelectrode+depth+recordings+from+microelectrode+data+or+vice+versa.+Also+lacking%2C+so+far%2C+is+any+general+understanding+of+the+relation+of+slower%2C+local+field+potentials+and+spike+firing.+Examples+are+known+of+strong+positive+correlations+and+others+show+no+correlation.+Communication+among+neurons+by+subthreshold%2C+nonsynaptic+routes+is+probably+important+in+some+evolving+places+and+times.%0A+%09The+relative+neglect+of+the+basic+biology%2C+natural+history%2C+evolution%2C+and+system+identification+of+local+field+potentials+at+different+scales+in+different+places+is+undeserved+and+a+prime+opportunity+for+new+tools+.&rft.publisher=Kjellberg%2C+Inc.&rft.contributor=Arikan%2C+K.&rft.contributor=Moore%2C+N.&rft.date=2002&rft.type=Book+Chapter&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F2572%2F2%2FIstanbul_MS.pdf&rft.identifier=++Bullock%2C+Professor+of+Neuroscience+Theodore+Holmes++(2002)+Biology+of+Brain+waves%3A+natural+history+and+evolution+of+an+information-rich+sign+of+activity.++%5BBook+Chapter%5D++++(In+Press)++&rft.relation=http%3A%2F%2Fcogprints.org%2F2572%2F