<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 13 juin 08, at 13:28, Stanley Klein wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Arno, you say the number of cycles of EEG gamma is between 6 and 12. But what about the recent Yuval-Greenberg article in Neuron pointing out that the kind of gamma often found in EEG has a much broader bandwidth (much fewer cycles) and is very tightly connected to an artifact of microsaccades after filtering the EEG. In a previous posting to eeglablist I had mentioned the poster by that group at the recent Cognitive Neuroscience meeting in San Francisco. Their article is now published at:<br> Neuron, Vol 58, 429-441, 08 May 2008<br><font size="2">Transient Induced Gamma-Band Response in EEG as a Manifestation of Miniature Saccades</font><br>Shlomit Yuval-Greenberg, Orr Tomer, Alon S. Keren,Israel Nelken,<a href="http://www.neuron.org/content/article/abstract?uid=PIIS0896627308003012#aff2" name="back-aff2" title=""></a> and Leon Y. Deouell<br> <a href="http://www.neuron.org/content/article/abstract?uid=PIIS0896627308003012#aff1" name="back-aff1" title=""></a><br>I look forward to an interesting discussion on the topic. They are clear that their conclusion is specifically for EEG, not to evidence of gamma in ECoG or microelectrode studies.</blockquote><div><br></div><div><br></div><div>According to the original reference, these "artifacts" (although it could also be potentially interesting to study them) mostly arise with nose reference data. Also, they occur very early after the stimulus presentation and any type of gamma effect found after 200 ms could not be attributed to them. There is a comment/response by P. Fries in Neuron too about this paper showing some genuine gamma in both MEG and EEG scalp recording.</div><div><br></div><div>As far as the number of cycle go, I am only reporting what I know about the literature. I agree with you that it is not because it is in the literature that it is necessarily optimal.</div><div><br></div><div>Best,</div><div><br></div><div>Arno</div></div></body></html>