<?xml version="1.0" encoding="utf-8"?><!DOCTYPE article  PUBLIC '-//OASIS//DTD DocBook XML V4.4//EN'  'http://www.docbook.org/xml/4.4/docbookx.dtd'><article><articleinfo><title>maxintro</title><revhistory><revision><revnumber>9</revnumber><date>2014-04-04 09:37:54</date><authorinitials>RikHenson</authorinitials></revision><revision><revnumber>8</revnumber><date>2013-03-08 10:02:15</date><authorinitials>localhost</authorinitials><revremark>converted to 1.6 markup</revremark></revision><revision><revnumber>7</revnumber><date>2008-03-11 15:36:29</date><authorinitials>YuryShtyrov</authorinitials></revision><revision><revnumber>6</revnumber><date>2008-03-11 15:33:37</date><authorinitials>YuryShtyrov</authorinitials></revision><revision><revnumber>5</revnumber><date>2008-03-11 15:31:28</date><authorinitials>YuryShtyrov</authorinitials></revision><revision><revnumber>4</revnumber><date>2008-03-11 15:30:45</date><authorinitials>YuryShtyrov</authorinitials></revision><revision><revnumber>3</revnumber><date>2008-03-11 15:26:16</date><authorinitials>YuryShtyrov</authorinitials></revision><revision><revnumber>2</revnumber><date>2008-03-11 15:25:52</date><authorinitials>YuryShtyrov</authorinitials></revision><revision><revnumber>1</revnumber><date>2008-03-11 15:25:38</date><authorinitials>YuryShtyrov</authorinitials></revision></revhistory></articleinfo><section><title>Maxfilter</title><para>A common first step in analysing your data is to pre-processing them using the Maxfilter program. This Neuromag sofware implements &quot;Signal-Space Separation&quot; (SSS), which is a clever mathematical way to separate magnetic signals coming from within the brain (or more precisely, a sphere within the sensors) from those coming from outside the brain (or more precisely, from outside a sphere outside the sensors). Some PDFs that describe the SSS mathematics are here: <ulink url="https://lsr-wiki-01.mrc-cbu.cam.ac.uk/meg/maxintro/meg/maxintro?action=AttachFile&amp;do=get&amp;target=Taulu_IEEE_05.pdf">Taulu_IEEE_05.pdf</ulink> , <ulink url="https://lsr-wiki-01.mrc-cbu.cam.ac.uk/meg/maxintro/meg/maxintro?action=AttachFile&amp;do=get&amp;target=Taulu_JAP_05.pdf">Taulu_JAP_05.pdf</ulink> , <ulink url="https://lsr-wiki-01.mrc-cbu.cam.ac.uk/meg/maxintro/meg/maxintro?action=AttachFile&amp;do=get&amp;target=Taulu_PMB_06.pdf">Taulu_PMB_06.pdf</ulink> . </para><para>Maxfilter is essential if you have acquired your data using Maxshield (to remove the shielding effects). It is also helpful for 1) removing noise, particularly using its &quot;temporal extension&quot;, 2) detecting bad channels, 3) realigning (interpolated) data after movement (provided you have used continuous HPI) and 4) moving the data to a standard space (e.g, across subjects). </para></section></article>