[Eeglablist] Meaning of ITC

[Makoto Miyakoshi]

Dear Pal,

Thank you for your fast response and information.
Neurovascular coupling is the essential phenomenon with BOLD and it has
totally different time constant than EEG... that is fine with me. That
said, what I'm wondering is the meaning of ITC. On the one hand, ERSP is a
　measure of EEG power, which most likely reflects sum of regional neuronal
activities, which should be associated with BOLD via neurovascular coupling
(in principle). On the other hand, ITC has nothing to do with EEG power,
since it is a measure of inter-trial phase variance, therefore it should
not affect BOLD either. Then, what is the meaning of ITC in contrast with
ERSP/BOLD?


Makoto



> --- P将ゥl Gunnar Larsson <Pal.Gunnar.Larsson at epilepsy.no> wrote:
> 
> > I think you should read the paper by PL Nunez on the relation
> between
> > EEG and fMRI from 2000 (or 1999?). EEG and BOLD is very different
> > entities. Also, the EEG- parameters are direct functional measures
> > which gives responsen from a few miliseconds to some seconds
> > (Pfurtscheller). BOLD on the other hand, is the change in
> oxygenation
> > due to change in bloodflow due to change in energy consumption due
> > change in activity. Hence the effect is very indirect and shows a
> > maximum after some 5s. E.G. AM Dale et al has shown some nice use
> of
> > the BOLD and EEG/MEG so there no reason to discard one, just use
> with
> > care.
> > 
> > Pセュ自l
> > 
> > -----Opprinnelig melding-----
> > Fra: eeglablist-bounces at sccn.ucsd.edu
> > [mailto:eeglablist-bounces at sccn.ucsd.edu] Pセュ自 vegne av Makoto
> > Miyakoshi
> > Sendt: 10. april 2009 11:25
> > Til: eeglablist at sccn.ucsd.edu
> > Emne: [Eeglablist] Meaning of ITC
> > 
> > Dear experts,
> > 
> > Let me take a question about a basic physiology.
> > In my intuition, ERSP (i.e. EEG power) is related to neuronal 
> > activation, either firing frequency or number of firing cells. On
> the
> > other hand, ITC (i.e. inter-trial EEG phase) is NOT directly
> related
> > to them. So, by observing ITC, we may be observing some already
> > systematized temporal responsibility of the given network, which is
> > too complicated and abstract to imagine, compared to the case of
> > neuronal firing simply increasing/decreasing.  Does it mean, then,
> > ITC is a totally different index than, for example, BOLD?
> > 
> > Makoto
> > _______________________________________________
> > Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> > To unsubscribe, send an empty email to
> > eeglablist-unsubscribe at sccn.ucsd.edu
> > For digest mode, send an email with the subject "set digest mime"
> to
> > eeglablist-request at sccn.ucsd.edu
> > 
> 
>