Re: request for info

["Dr. Richard Welser" <duffy@HCI.NET>]

Dear Erik,

It's been a while since I did this kind of research but I would suggest
that the common idea that higher spectra indicate greater activity is
not a truism. Also, I would suggest using ERP's rather than power
spectra, or use both since you can obtain both independent measures from
an ERP paradigm. Good people to consult with might include Dr. Dennis
Molfese and Dr. David G. Gilbert at Southern Illinois University in
Carbondale, Illinois, USA. They are in separate labs, Dave uses
primarily Intel-based machines and Dennis uses Macintosh computer
systems and has a well-proven ERP software package developed at that lab
to analyze ERPs. I worked with both psychologists and can attest that
they are both very sharp. Check their articles out. They have both been
prolific and you may get quite a lot of ideas from their articles and
methodology sections.
Sincerely,
Dr. Richard Welser
Clinical Neuropsychologist
Broughton Hospital
Morganton, NC USA


Erik Nordh wrote:

> Forwarded message to the list; please answer directly to the original
> sender  <ophoon@yahoo.com>.
>
> Regards
> /Erik
>
> >Date: Sat, 30 Oct 1999 01:55:32 -0700 (PDT)
> >From: Ong Puay Hoon <ophoon@yahoo.com>
> >Subject: request for info
>
> >I'm a postgrad student, intending to use EEG to study
> >brain functions during mathematics tasks with focus on
> >cortical activations at the hemispherical level. Using
> >the Int. 10-20 system for 16 cortical sites and brain
> >wave spectrum 0-40Hz, the software that our EEG
> >recording machine has is only able to compute the
> >power spectra values at each cortical site for each
> >wave band. My readings seem to indicate the higher the
> >spectra values, the greater is the brain activity. Is
> >this true?
> >Further, how can I go about analyzing coherence and
> >cross-coherence with this software? What other kinds
> >of analysis can I do with the EEG data?
> >Hope to hear from you.
> >Ong Puay Hoon
> >University Malaysia Sarawak
> >