netstation tags

[Jeff Maxwell]

Hi Yan,
I can't test this with an EGI system at my present location, but have
a couple of thoughts.

First, have you synchronized your clock on EPrime Biological using the
photodiode to determine (a) the baseline/constant offset between the
PC-Mac timing, and (b) if/what drift (i.e. increase) in this timing
occurs over extended periods of testing?  Once you've determined
these, you can set a scaling factor to synchronize the clocks.  This
should take care of the majority of both issues.  If there is a
residual offset of a few milliseconds, it should be fixed and so can
easily be accounted for.  How to do all of this is covered in the
EPrime Biological documentation that you should have received through
EGI.

Second, have you used the DIN (Parallel Port) lines at the same time
as the serial information to ensure that your correct timing in the
.edat files is corroborated by correct timing in the instantaneous
event coding?  If not, you should do this as well.

Finally, unrelated to your question but perhaps saving a lot of time
down the line, there are many keys/levels of serial event coding
available in EPrime Biological.  I haven't used the newest versions of
NetStation and EPrime Bio, but in my experience, segmentation and
post-processing is MUCH easier if you skip most of these levels and
code all of your events using unique "tags".  There are a nearly
infinite number of alphanumeric 4-key combinations and accessing these
in the exported files (e.g., in MatLab), and even within the EGI
software, is much more straightforward than the various
cells/keys/levels.

Hope something in this helps,
Max





On 10/22/08, Yan Yu <yanhyu at gmail.com> wrote:
> Dear eprimers,
>
> I am delivering stimulus via eprime and collecting ERP data via
> NetStation. However, for some reason, when I do my AV test, the delay
> is very large.
> I am wondering if I did anything wrong. Here attached is my
> experiment, Basically, I have 8 type of sentence lists, each list is a
> paragraph of a story. In each sentence, I need to tag the onsets of
> several particular words.I used a seperate marker list to send tags to
> netstation. My inter-sentence interval is 500ms as defined by "wait3".
> Because the interval between two adjacent target words varies, I used
> an inline object to ask eprime to calculate the interval of the two
> words before marking.   Could any expert do me a favor to check
> whether my tags are doing the right job? What might be the reason for
> the huge delays I am getting? How to reduce that delay? One thing that
> puzzles me is: when I check the edat file, the delay is quite
> neglectible, only the delay on my netstation IV test is very large.
>
> Thanks a lot in advance!
>
> Yan
>
> >
>
>

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "E-Prime" group.
To post to this group, send email to e-prime at googlegroups.com
To unsubscribe from this group, send email to e-prime+unsubscribe at googlegroups.com
For more options, visit this group at http://groups.google.com/group/e-prime?hl=en
-~----------~----~----~----~------~----~------~--~---