http://fieldtrip.fcdonders.nl/ 2010-07-29T23:31:19+02:00 http://fieldtrip.fcdonders.nl/ http://fieldtrip.fcdonders.nl/lib/images/favicon.ico text/html 2010-07-29T15:50:54+02:00 Vladimir Litvak http://fieldtrip.fcdonders.nl/integrating_with_spm8?rev=1280411454&do=diff Background SPM8 is the newest version of SPM software developed by the Methods Group at the Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, UK and collaborators. SPM8 implements several advanced methods for M/EEG analysis: text/html 2010-07-28T12:59:50+02:00 Jan-Mathijs Schoffelen http://fieldtrip.fcdonders.nl/dataformat?rev=1280314790&do=diff dataformat, meg, eeg, lfp, spike FieldTrip has a flexible way of supporting data formats. It uses three wrapper functions that provide a common interface to all electrophysiological (EEG/MEG) file formats: ft_read_header, ft_read_data and ft_read_event. These wrapper functions will call the low-level functions for each file format. Some of the low-level functions are written by ourselves, others are supplied by the manufacturers and again others are obtained from other open source toolb… text/html 2010-07-28T11:11:46+02:00 Jan-Mathijs Schoffelen http://fieldtrip.fcdonders.nl/faq/how_are_the_various_data_structures_defined?rev=1280308306&do=diff faq, datatype, todo TODO complete the description of the main data formats (raw, comp, timelock, freq, source, volume) How are the various data structures defined? The output of a FieldTrip function is a data structure of a particular type. Such data structure consists at least of numeric data specific to that particular datatype, and of descriptive fields which are needed to interpret the data. The different datatypes and their features are listed below: text/html 2010-07-28T11:05:14+02:00 Jan-Mathijs Schoffelen http://fieldtrip.fcdonders.nl/faq/what_does_a_typical_call_to_a_fieldtrip_function_look_like?rev=1280307914&do=diff faq, datatype, function What does a typical call to a FieldTrip function look like? The FieldTrip functions in general work like this dataout = functionname(cfg); % e.g. ft_preprocessing dataout = functionname(cfg, datain, ...); % e.g. ft_freqanalysis functionname(cfg, datain, ...); % e.g. plotting functions Type 'help functionname' to see which input arguments (cfg.xxx) ought to be defined before calling the function. The datain and dataout arguments to all F… text/html 2010-07-28T10:57:50+02:00 Jan-Mathijs Schoffelen http://fieldtrip.fcdonders.nl/faq?rev=1280307470&do=diff faq On this page you can find (and add) answers to a variety of Fieldtrip-related questions. We invite you to add your own example scripts or frequently asked questions on the wiki. Also tutorials can be added. Every time you explain somebody something about Fieldtrip, please consider whether you could use the wiki for this so others can learn from it as well. text/html 2010-07-27T15:20:25+02:00 http://fieldtrip.fcdonders.nl/tutorial/forward?rev=1280236825&do=diff Introduction The goal of this tutorial is to give insights about biological electric-magnetic fields generated at the neural level and how this impacts signals from EEG, MEG, ECoG, single cell recordings, tetrodes, etc. A so-called forward solution is here intended as the set of equation which lead from sources in the brain to the signal recorded at the sensor level. The spatial pattern of activation corresponding to a specific neural source is called most of the times 'lead field'. The availa… text/html 2010-07-27T10:56:37+02:00 Jan-Mathijs Schoffelen http://fieldtrip.fcdonders.nl/faq/why_does_my_tfr_look_strange?rev=1280220997&do=diff faq, ft freqanalysis, ft freqanalysis mtmconvol, freq, tfr Why does my TFR look strange? If you use 'mtmconvol' as a method for frequency analysis it could happen that the Time-Frequency Representation of your data looks like this: This phenomenon is caused by the time domain data having a non-zero DC component. This component leaks into the estimates of all time-frequency points in a variable (but patterned) way. The reason why this actually happens is related to the exact algorithm…