[Eeglablist] Filter causality pop_eegfiltnew

Vito de Feo vito.defeo at zmnh.uni-hamburg.de
Thu Jan 16 10:42:55 PST 2014


  Dear Makoto,

I attach you a couple of papers that illustrate the problems. To explain
quickly the problem it is obvious that if you filter in both the directions
(as an acausal filter does) you introduce a correlation beetwen the
"future" and the "past".

I need to filter the data to remove the 50 HZ (or 60 Hz if you are in USA
or Japan) frequency. For the rest I don't filter.

Best

Vito

Quoting Makoto Miyakoshi <mmiyakoshi at ucsd.edu>:

> Dear Vito,       
>    > the acausal filtering destroy the causality flow. For Granger it is
> important to use only causal filter.
>     
>    Oh really. That sounds counterintuitive to me. Please send me the URL
> to the paper about it.
>     
>    However let me tell you this that Tim Mullen (the author of SIFT)
> told us in the past EEGLAB workshop that we should not use ANY filter
> for SIFT. If you want to remove low-frequency drifts etc... he
> recommended the detrend option supported in SIFT. For low-pass filter,
> he said don't use it. Also make sure that you use double precision, not
> signle precision; check EEGLAB option to switch it (default should be
> single precision). Actually these were new things I learned!
>     
>    Condro, for clarification to novice users, let me add this that
> EEGLAB's FIR filter is by default non-causal (i.e. peak latencies do not
> shift).
>     
>    Makoto
>
>     2014/1/15 Vito de Feo <vito.defeo at zmnh.uni-hamburg.de>
>
>> _Dear Makoto,
>>
>> the acausal filtering destroy the causality flow. For Granger it is
>> important to use only causal filter. If you are interested I can send
>> you a paper about that.
>>
>> Yes, I know SIFT and I am also using it for my analisys._
>>
>>
>> _Vito
>>
>> Quoting Makoto Miyakoshi <mmiyakoshi at ucsd.edu>:_
>>
>>         
>>
>>> _Dear Andreas and Vito, _                     _ _
>>>            _Sorry Andreas I screwed it when I typed your name._
>>>            _ _
>>>            _Vito, I would like to learn from you the reason why you
>>> want to use the minimum phase filter for Granger causality analysis.
>>> By the way, you know SIFT is available for it? In case you don't know
>>> it yet, check out http://sccn.ucsd.edu/wiki/SIFT._
>>>            _ _
>>>            _Makoto_
>>>
>>>
>>>
>>>            _2014/1/14 Vito de Feo <vito.defeo at zmnh.uni-hamburg.de>_
>>>
>>>> _Dear Andreas,
>>>>
>>>> I download the last version (13.1.1) and now the option is present
>>>> and it is clearly written that the default is the zero-phase linear
>>>> filtering.
>>>>
>>>> In my previous version (the last of the EEGLAB 12) this option was
>>>> not present but now, with the version 13, it is present again!
>>>>
>>>> Best,
>>>>
>>>> Vito _
>>>>
>>>> _Quoting Andreas Widmann <widmann at uni-leipzig.de>:_
>>>>
>>>>> _Dear Vito,_
>>>>>
>>>>>> _in the last eeglab version there is not the minphase parameter in
>>>>>> the pop_eegfiltnew function._
>>>>>
>>>>> _Which version is your last version? In 13.1.1 from the web page and
>>>>> in rev 10261 from SVN the option is present. It was initially
>>>>> introduced in EEGLAB 13 (but not backported to EEGLAB 12). Could you
>>>>> please check whether possibly something went wrong with your
>>>>> setup/path and report back your version number?_
>>>>>
>>>>>> _It was useful to force the filter to be causal. If I have
>>>>>> understand well now the filter is causal by dafault because it uses
>>>>>> the filter funcion. Is this correct?_
>>>>>
>>>>> _NO! Causal non-linear filter is NOT the default. Default is and
>>>>> will remain zero-phase linear filtering. Default filter functions
>>>>> did not change since EEGLAB 12.
>>>>>
>>>>> Best,
>>>>> Andreas_
>>>>>
>>>>>> _Sorry if this is a vey well known issue but I didn't find any
>>>>>> answer on the web until now.
>>>>>> I need filter causality for Granger analisys. If anyone has also
>>>>>> other suggestion about causal filtering with eeglab, any suggestion
>>>>>> is very welcome!
>>>>>>
>>>>>> Thank in advange!
>>>>>>
>>>>>> Vito
>>>>>>
>>>>>> --
>>>>>> Pflichtangaben gemäß Gesetz über elektronische Handelsregister
und
>>>>>> Genossenschaftsregister sowie das Unternehmensregister (EHUG):
>>>>>>
>>>>>> Universitätsklinikum Hamburg-Eppendorf
>>>>>> Körperschaft des öffentlichen Rechts
>>>>>> Gerichtsstand: Hamburg
>>>>>>
>>>>>> Vorstandsmitglieder:
>>>>>> Prof. Dr. Christian Gerloff (Vertreter des Vorsitzenden)
>>>>>> Prof. Dr. Dr. Uwe Koch-Gromus
>>>>>> Joachim Prölß
>>>>>> Rainer Schoppik
>>>>>>
>>>>>> ________________________________________________
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>>>>>>
>>>>>> _--
>>>>>> Makoto Miyakoshi
>>>>>> Swartz Center for Computational Neuroscience
>>>>>> Institute for Neural Computation, University of California San Diego
>>>>>> ________________________________________________
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>>>>
>>>> ____--
>>>> Pflichtangaben gemäß Gesetz über elektronische Handelsregister und
>>>> Genossenschaftsregister sowie das Unternehmensregister (EHUG):
>>>>
>>>> Universitätsklinikum Hamburg-Eppendorf
>>>> Körperschaft des öffentlichen Rechts
>>>> Gerichtsstand: Hamburg
>>>>
>>>> Vorstandsmitglieder:
>>>> Prof. Dr. Christian Gerloff (Vertreter des Vorsitzenden)
>>>> Prof. Dr. Dr. Uwe Koch-Gromus
>>>> Joachim Prölß
>>>> Rainer Schoppik____
>>>
>>>            _ _
>>> ____-- ____
>>>            ____Makoto Miyakoshi
>>> Swartz Center for Computational Neuroscience
>>> Institute for Neural Computation, University of California San
Diego____
>>
>> _--
>> Pflichtangaben gemäß Gesetz über elektronische Handelsregister und
>> Genossenschaftsregister sowie das Unternehmensregister (EHUG):
>>
>> Universitätsklinikum Hamburg-Eppendorf
>> Körperschaft des öffentlichen Rechts
>> Gerichtsstand: Hamburg
>>
>> Vorstandsmitglieder:
>> Prof. Dr. Christian Gerloff (Vertreter des Vorsitzenden)
>> Prof. Dr. Dr. Uwe Koch-Gromus
>> Joachim Prölß
>> Rainer Schoppik_
>
>      
> --
>     Makoto Miyakoshi
> Swartz Center for Computational Neuroscience
> Institute for Neural Computation, University of California San Diego



-- 
Pflichtangaben gemäß Gesetz über elektronische Handelsregister und Genossenschaftsregister sowie das Unternehmensregister (EHUG):

Universitätsklinikum Hamburg-Eppendorf
Körperschaft des öffentlichen Rechts
Gerichtsstand: Hamburg

Vorstandsmitglieder:
Prof. Dr. Christian Gerloff (Vertreter des Vorsitzenden)
Prof. Dr. Dr. Uwe Koch-Gromus
Joachim Prölß
Rainer Schoppik
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