[Eeglablist] Automated way of placing events

[Tarik S Bel-Bahar]

correction included below


On Tue, May 15, 2012 at 9:45 PM, Tarik S Bel-Bahar
<tarikbelbahar at gmail.com>wrote:

> Greetings Marco,
> this should be straightforward as a script, hope the outline below helps
> you generate your own script.
> Let us know if you succeed!
>
> 1. Make a loop that hunts for the the first, second, etc... instances of
> event A that marks the beginning of all trials.
> 2. Having found the first Event A, find the first Event B (which should be
> the start and end of 1 trial, according to you)
> 3. Take the latency value (in samples or milliseconds), of each of the two
> events.
> 4. Make a list of periods to drop for this trial, which should include the
> Time of Event A      and        the Time of Event A + 10Seconds   [this
> would be one period to "drop"]
>
   Time of Event B      and        the   Time of Event B - 10Seconds

>  [this would be the second period to "drop" for that file]
> 5. Update a list of times with these two sets of start and end values from
> Step 4.
> 6. Continue through the loop, adding to the array that holds the start and
> end values for the periods to drop.
> 7. Add an event if you need it to mark the start of each of your new
> "trimmed" trials. For example, the Time of Event A + 10 Seconds + 1 sample
> could be the place to put a new marker event for later epoching.
> 8. Reject the times you have collected.
> 9. Now Epoch based on other existing events within the trials.
>
>
> All of the baove you can build by doing a simple example from the GUI,
> then using eeg history information to build your own script.
>
> Also,* alternatively,* you *could *be able to also consider an
> alternative option,
> which simply would mean epoching on Event A,
> but setting the times to be  +10 seconds to plus however many seconds
> after Event A +10 seconds you want to go.
> This would work if your trial time of interest was not too variable, in
> other words, if the time
> between the first and last ten seconds in each trial were.
>
> As a last point, if you are using ICA, remember that you may be throwing
> out data that would be useful for a successful ICA decomposition.
>
>
>
> then copying out eegh  (eeg history), and then
>
>
>
>
> On Mon, May 14, 2012 at 2:33 PM, Marco Montalto <montaltomarco at onvol.net>wrote:
>
>> Dear Arno,
>>
>> I have tried the script you supplied me with but found a problem with it.
>> The first part of the script (EEG=pop_select….) treats the data file as one
>> continuous dataset; it ignores the events that mark the beginning and end
>> of a trial. I would like to remove the first and last ten seconds within
>> the boundaries of a trial delimited by the events marking the beginning and
>> end of a trial. As it is the script merely removes the first 10 seconds of
>> the continuous data and last ten seconds of the same continuous data. Let's
>> say A marks beginning of trial 1 and B marks the end of the same trial - I
>> would like to remove the first and last 10 seconds within the block marked
>> by events A and B. And so on for the rest of trails within the same data
>> file. Is this possible? Is there a way of doing this by using some script?
>> Any help you could provide me with would be greatly appreciated.
>>
>> Thanks and regards,
>> Marco
>>
>> On 11 May 2012, at 05:54, Arnaud Delorme wrote:
>>
>> Hi Marco,
>>
>> to do what you want to do, you should type in
>>
>> EEG = pop_select(EEG, 'time', [10 EEG.xmax-10]); % remove the first and
>> last 10 seconds
>> EEG = eeg_regepoch(EEG, 'recurrence', 2); % divide into 2 seconds
>> non-overlaping blocks
>>
>> Best,
>>
>> Arno
>>
>> On May 5, 2012, at 6:38 PM, Stephen Politzer-Ahles wrote:
>>
>> Hi Marco,
>>
>> I haven't tried this myself, but you should be able to get any of these
>> epochs from the same event using pop_epoch. Assuming that you have an event
>> marking the beginning of the block, then the first epoch you want (i.e.
>> 10-12 seconds after the event) would be
>>
>> OUTEEG = pop_epoch( EEG, {events}, [10 12]);
>>
>> the second would be
>>
>> OUTEEG = pop_epoch( EEG, {events}, [12 14]);
>>
>> etc.
>>
>> Best,
>> Steve
>>
>> On Sat, May 5, 2012 at 4:33 PM, Marco Montalto <montaltomarco at onvol.net>wrote:
>>
>>> Dear List,
>>>
>>> In my experiment I have three conditions and each trial is 30 seconds
>>> long. I ignore the first and last 10 seconds of each block and the middle
>>> 10-second block I divide into epochs of 2-second duration. Currently I am
>>> doing this manually through the EEGLAB GUI by placing an event (with the
>>> same 'type' for blocks from the same condition) at every two seconds (in
>>> the middle 10-second block) and then extracting epochs around those events.
>>> Would anyone know whether there is a more automated and a faster way of
>>> doing this? Thanks in advance.
>>>
>>> Regards,
>>> Marco Montalto
>>> _______________________________________________
>>> 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
>>>
>>
>>
>>
>> --
>> Stephen Politzer-Ahles
>> University of Kansas
>> Linguistics Department
>> http://www.linguistics.ku.edu/
>> _______________________________________________
>> 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
>>
>>
>>
>>
>> _______________________________________________
>> 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
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20120515/5b270800/attachment.html>