[Eeglablist] Question about channel locations for Biopac EDA dat

[Emily Cohodes]

Hi James,

Apologies for my significant delay in getting back to you! I followed your instructions re: adjusting the display and the wave form is now visible in the plotting window! I was also able to successfully load in my event file following your instructions (and these show up in the plotted wave). Thank you so much for your help! 

I am now trying to export the EDA data with event markers so that I can import the data back into AcqKnowledge for analysis. I tried using the “Data to EDF/BDF/GDF file” option but this does not seem to actually be creating an EDF file that AcqKnowledge can view via the import function. I am getting the following warning, in case this is helpful:

Recreating event channel
Warning SOPEN (EDF-Write): relative scaling error is 2.129597e-06 (due to roundoff in PhysMax/Min)
Warning SWRITE: 480 NaNs added to complete data block.
Done.

I am seeing a new file appear in the path location that I specify but this is not readable by AcqKnowledge as an EDF file, for example. Do you have any general recommendations for exporting the wave with events back into AcqKnowledge? I had only selected the EDF option because I see that this is one of the file types that AcqKnowledge accepts. 

Thank you again for all of your help and please let me know if it would be helpful for me to provide any additional information. I greatly appreciate your assistance! 

Best,
Em
_________________
Emily Cohodes
PhD Student, Clinical Psychology
Clinical Affective Neuroscience and Development Lab
Yale University
2 Hillhouse Avenue
New Haven, CT 06520

> On Apr 25, 2017, at 12:46 PM, James Jones-Rounds <jj324 at cornell.edu> wrote:
> 
> >>  It might be helpful to note that even before putting in the event info, I am not able to plot the wave in EEGLAB. 
> 
> Does that mean the plotting function doesn't even put a window on the screen, or spits out an error to the MATLAB command window, when you go to "Plot > Channel data (scroll)" ?
> 
> Or do you mean that when you do plot the data, you can't see any wave forms in the plotting window? 
> 
> If it's just that you don't see any wave forms in the plotting window, that might be because of the y-axis range, or a related "offset" issue. On the plot figure menu, try clicking "Display > Remove DC Offset". That might re-center your plotting window onto the data wave-form. Then you can play around with the y-axis range on the bottom right text-input box, that has the "+" and "-"  next to it.
> 
> On Tue, Apr 25, 2017 at 12:39 PM, Emily Cohodes <emily.cohodes at yale.edu <mailto:emily.cohodes at yale.edu>> wrote:
> Hi James,
> 
> Thanks for your quick reply! I’m glad to hear that channel location info is not necessary and that there must be an issue with how I’m formatting either the wave or event files. 
> 
> I have imported the BIOPAC-specific data import extension for EEGLAB and am exporting my data from Acqknowledge in a “.mat” format. It might be helpful to note that even before putting in the event info, I am not able to plot the wave in EEGLAB. 
> 
> Any further thoughts you may have/suggestions for troubleshooting would be very much appreciated!
> 
> Best,
> Emily
> __________________
> Emily Cohodes
> PhD Student, Clinical Psychology
> Clinical Affective Neuroscience and Development Lab
> Yale University
> 2 Hillhouse Avenue
> New Haven, CT 06520
> 
>> On Apr 25, 2017, at 8:32 AM, James Jones-Rounds <jj324 at cornell.edu <mailto:jj324 at cornell.edu>> wrote:
>> 
>> Hi Emily,
>> 
>> If you have successfully imported your data file from Acqknowledge into EEGLAB, then you should be able to plot the data from the EDA channel (you're referring to skin conductance, right?) regardless of whether you have channel location data. This is the same for any data imported to EEGLAB. Some topographic-related functions (like plotting a scalp map) require channel locations, and most advanced functionalities in the data do too. But just plotting the time series data does not require that. 
>> 
>> I suspect, however, that the data is not being imported properly. Have you installed the BIOPAC-specific data import extension for EEGLAB? If so, you might see that it expects the BIOPAC data to be in a ".mat" format, which you can save your .acq files in if you do "Save as" in Acqknowledge.
>> 
>> Or do you mean that your events aren't showing up in the time-series plot? In that case I think you should double-check that the event matrix that you're feeding into the "pop_importevent" is formatted correctly. If you're using the "pop_chanevent" function instead, because you have a BIOPAC channel that was functioning as your stimulus event code channel, then try playing with the settings of that function to make sure it's importing your events properly. Good luck!
>> 
>> James
>> 
>> 
>> ---------- Forwarded message ----------
>> From: Emily Cohodes <emily.cohodes at yale.edu <mailto:emily.cohodes at yale.edu>>
>> To: <eeglablist at sccn.ucsd.edu <mailto:eeglablist at sccn.ucsd.edu>>
>> Cc: 
>> Bcc: 
>> Date: Fri, 21 Apr 2017 07:51:06 -0400
>> Subject: [Eeglablist] Question about channel locations for Biopac EDA data
>> Hi eeglablist, 
>> 
>> I am trying to batch enter event markers for an EDA file (collected using Biopac/AcqKnowledge) that I have exported into eeglab. Currently, the file is reading in the events but is not able to plot It either in eeglab or when I export it back to AcqKnowledge. I am guessing that I need to read in channel locations in order for it to plot. Does anyone know where I can find the correct channel locations for EDA data collected with Biopac to use in eeglab or how to set this up? 
>> 
>> Thanks in advance for your help!
>> 
>> Best,
>> Emily
>> __________________
>> Emily Cohodes
>> PhD Student, Clinical Psychology
>> Clinical Affective Neuroscience and Development Lab
>> Yale University
>> 2 Hillhouse Avenue
>> New Haven, CT 06520
>> -- 
>> James Jones-Rounds
>> Laboratory Manager
>> Human Development EEG and Psychophysiology (HEP) Laboratory,
>> Department of Human Development,
>> --------------------------------------------
>> Cornell University | Ithaca, NY
>> 607-255-9883 <tel:(607)%20255-9883>
>> eeg at cornell.edu <mailto:eeg at cornell.edu>
> 
> 
> 
> -- 
> James Jones-Rounds
> Laboratory Manager
> Human Development EEG and Psychophysiology (HEP) Laboratory,
> Department of Human Development,
> --------------------------------------------
> Cornell University | Ithaca, NY
> 607-255-9883
> eeg at cornell.edu <mailto:eeg at cornell.edu>
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