<html><head><base href="x-msg://401/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Ana,<div><br></div><div>at the lowest frequency, your moving window size is 824 ms, so if your epoch starts at -1500 ms, the center of the first window is located at -1088 ms. Because we only get spectral estimates at the center of windows, this is why you "loose" data on the edge. </div><div><br></div><div>And this is what we generally mean by "border" effect (although it can also be what Makoto was talking about). I have not heard of edge artifacts. However, you must remember that the window you use at the lowest frequency include a total of 824 ms of data although it is tapered (multiplied) by a gaussian (in the case of Morlet wavelets) to avoid window edge effects.</div><div><br></div><div>Best,</div><div><br></div><div>Arno</div><div><br><div><div>On 21 Mar 2013, at 00:11, Ana Navarro Cebrian wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div class="hmmessage" style="font-size: 12pt; font-family: Calibri; "><div dir="ltr"><span style="color: rgb(68, 68, 68); font-size: 15px; line-height: 21px; ">Dear eeglab users,</span><div style="line-height: 21px; color: rgb(68, 68, 68); font-size: 15px; ">I'm using newtimef to calculate the ERSP. My epochs are -1500 to 2000 ms long, and I'm using the time from -1500 to 0 as a baseline. </div><div style="line-height: 21px; color: rgb(68, 68, 68); font-size: 15px; ">I've been told that a baseline from -500 to -200 ms would be more optimal to avoid edge-artifacts, since my baseline starts at the same point that the beginning of my epoch (-1500ms). </div><div style="line-height: 21px; color: rgb(68, 68, 68); font-size: 15px; "><br></div><div style="line-height: 21px; color: rgb(68, 68, 68); font-size: 15px; ">I don't observe any edge effects in my data (with the -1500 to 0 ms as a baseline), but I don't have other way to verify this and I'd like to make sure of it. Also, I believe that this is related to the fact that my ERSP plots only show from around -1088ms to 1586ms (instead of -1500 to 2000), but I would like to understand this better.</div><div style="line-height: 21px; color: rgb(68, 68, 68); font-size: 15px; ">Could anybody explain why I shouldn't worry about edge artifacts when using newtimef to calculate the ERSPs?</div><div style="line-height: 21px; color: rgb(68, 68, 68); font-size: 15px; ">Many thanks,</div><div style="line-height: 21px; color: rgb(68, 68, 68); font-size: 15px; ">Ana<span style="font-size: 12pt; "> </span></div><pre> </pre></div>_______________________________________________<br>Eeglablist page:<span class="Apple-converted-space"> </span><a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a><br>To unsubscribe, send an empty email to<span class="Apple-converted-space"> </span><a href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu">eeglablist-unsubscribe@sccn.ucsd.edu</a><br>For digest mode, send an email with the subject "set digest mime" to<span class="Apple-converted-space"> </span><a href="mailto:eeglablist-request@sccn.ucsd.edu">eeglablist-request@sccn.ucsd.edu</a></div></span></blockquote></div><br></div></body></html>