Help_about 'time-frequency represengtations of power'

Weina Li lwn_07 at YAHOO.COM.CN
Tue Nov 13 09:59:30 CET 2007


hello!
   I am a new learner in MEG signal processing by using fieldtrip. And I 
need some help in understanding the tutorials of time-frequency 
represengtations of power.

  In the tutorials of calculating TFRs with frequency dependent window 
length,there is a sentence "The analysis is best done by first selecting 
the numbers of cycles per time window which will be the same for all 
frequencies"; and "When choosing this parameter it is important that a 
full number of cycles fit within the time-window for a given frequency".
---so what is 'cycles' mean? How can explain it? 

and "cfg.t_ftimwin    = 7./cfg.foi;  % 7 cycles per time window"
---then does the cycles has any relation to the frequency of interest?  
How should I select the number of cycles, is there a rule?


    Thanks!
           
                                                                           
                    Weina Li
                                                                           
                  Chongqing,China

----------------------------------
The aim of this list is to facilitate the discussion between users of the FieldTrip  toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/fcdonders/fieldtrip.



More information about the fieldtrip mailing list