Comparative computations of spike synchronization in visual cortex of cats.
In recent years it has been proposed that synchronous activity between neurons is a putative mechanism to bind together various trigger features of an image. Thus the measure of synchronization becomes an important issue since it may be an electrophysiological sign of visual perception. This paper describes and compares six techniques of computing synchronization strength, that is, the central peak of a cross-correlogram. Data were obtained in anesthetized cats prepared for electrophysiological recordings in a conventional fashion. Results indicate that: (1) eye fits are misleading. Visual inspection of cross-correlograms, may be interesting if one needs to estimate approximately synchronization strength and the presence of oscillations in the cross-correlograms, however it may be misleading if one wants to compare different cross-correlograms; (2) regression analysis to compare one method against the others yields a relatively poor correlation suggesting that methods are not directly comparable; (3) the sensitivity of each computational method is unequal. The results may indicate that some functional connections are either under- or over-evaluated depending upon the strategy employed to measure synchronization.
Molotchnikoff
S
S
Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, Québec, Canada H3C 3J7. molotchn@ere.umontreal.ca
Aïtoubah
J
J
Bretzner
F
F
Shumikhina
S
S
Tan
Y F
YF
Guillemot
J P
JP
D000818:Animals; D016477:Artifacts; D002415:Cats; D003344:Cortical Synchronization / Q000379:methods*; D012044:Regression Analysis; D014793:Visual Cortex / Q000502:physiology*