Response to: Yuval-Greenberg et al., 'Transient Induced Gamma-Band Response in EEG as a Manifestation of Miniature Saccades.' Neuron 58, 429-441.

摘要

Synchronized oscillatory activity in the gamma frequency range has been proposed as a neuronal mechanism for various cognitive processes, ranging from perceptual binding (Singer, 1999) to motor control (Schoffelen et al., 2005). In a recent paper in Neuron, Yuval-Green-berg et al. (2008) claim that induced gamma oscillations recorded by scalp electroencephalography (EEG) reflect miniature saccades instead of cognitive or neuronal processes. Combining high-precision eye tracking with EEG recordings, Yuval-Greenberg et al. found that (1) the induced gamma band response (iGBR) follows similar temporal dynamics as miniature saccade rate after display change, (2) only trials containing miniature saccades and its electrophysiological counterpart, namely the spike potential (SP), contribute to the iGBR, (3) with a nose reference montage, the time frequency decomposition of the SP shows a maximum over centro-parietal electrodes, (4) the iGBR amplitude correlates with the rate of miniature saccades, and (5) the difference between conditions in ' terms of iGBR can be attributed td1 differences in miniature saccade rate and amplitude. Based on these findings, Yuval-Greenberg et al. conclude that the "iGBR is ocular rather than neuronal." The generality of this conclusion is questionable based on several points: