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<body dir="ltr"><p><span style="padding: 3px 10px; border-radius: 5px; color: #ffffff; font-weight: bold; display: inline-block; background-color: #ff0000;"> External Email - Use Caution </span></p><p></p>
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Hello,</div>
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I want to perform event related analysis on some high frequency amplitude of some ECoG signals.</div>
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I apply raw.filter() and raw.apply_hilbert(envelope=true) in the frequency band of interest on my initial data.</div>
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<div>T<span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;">he resulting HFB envelope contains only positive values, as an amplitude should.</span></div>
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<div><span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;">Strangely once I epoch the envelope with mne.epoch() using some equally spaced stimulus releated events, the resulting epochs contain some negative
value in their entries. But is does not seems that epoching shift the origin x axis or does it? </span><br>
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<div>I know that I can also extract the envelope directly from epoched data but this a confusing observation and would appreciate some explanation of what could go wrong if anybody has <span id="🙂">🙂</span></div>
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<div><span>Cheers,</span></div>
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<div><span>Guillaume Corlouer</span></div>
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