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<p class="MsoNormal"><span lang="EN-GB">Hello, <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">My question concerns the Fieldtrip PSD function. I am running the code on some EEG data and comparing it with the MATLAB periodogram function. While the FFT produces similar graphical shape of the spectrogram, the units
are different. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">The periodogram function’s units are µV^2/Hz, which is the common output for power (before converting to Db). However, the values that I get with the Fieldtrip freqanalysis function seem to be ~120 times lower. I cannot
understand what they are. I looked at the code and still do not get it. I suppose that this is due to some normalization method done but I am not certain as to the rationale for the particular one used.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Tanks.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:16.0pt;font-family:Mistral;mso-fareast-language:SV">/Adam</span><span lang="EN-GB" style="mso-fareast-language:SV"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Arial Nova",sans-serif;color:#7F7F7F;mso-fareast-language:SV">______________________________________________________________________________________</span><span lang="EN-GB" style="mso-fareast-language:SV"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Arial Nova",sans-serif;color:#7F7F7F;mso-fareast-language:SV">Adam Grinberg, PT, PhD</span><span lang="EN-GB" style="mso-fareast-language:SV"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-family:"Arial Nova",sans-serif;color:#7F7F7F;mso-fareast-language:SV">Department of Community Medicine and Rehabilitation, Physiotherapy</span><span lang="EN-GB" style="mso-fareast-language:SV"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial Nova",sans-serif;color:#7F7F7F;mso-fareast-language:SV">Umeå University<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial Nova",sans-serif;color:#7F7F7F;mso-fareast-language:SV">Umeå, Sweden<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial Nova",sans-serif;color:#7F7F7F;mso-fareast-language:SV">Tel: +46 (0) 90 786 96 30<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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