Data import from "Presetation" .log

Hi there,

We’re currenly using this program, called Presentation (Neurobehavioral Systems), for our research in evented (visual) evoked potentials. Here is a link, if it’s needed http://www.neurobs.com/menu_presentation/menu_features/features_overview
So the program creates a .log file, where stimulation (we’re using pictures of familiar/unfamiliar faces as a stimuli) file name, time of stimulation and other data are included. All stimuli and time, related to stimuli, are unique; and we need, if it’s possible, stimulation file names (named as “code” in log file) and time of stimulation (“time”) to be imported somehow into a Brainstorm. To be precise - to import stimulation and time as an events.

Sincerely,

Vitaly Podlepich
Kirill Nezhdanov

P.S. One stimulation name corresponds to one time period

Trial Event Type Code Time
1 Picture p0908 109
2 Picture p0312 25399
3 Picture p0115 50825
4 Picture p1909 76223
5 Picture p0307 101797
6 Picture p0104 127396
7 Picture p0702 153098
8 Picture p0314 178431

This is an example of our .log file

Hello,

I could add the support for these .log files as event markers.
You would load them from the Record tab, menu File > Add events from file.
Is this what you need?

If so, can you give me a few more information:

  • What are the units for the time? are these sample indices?
  • How do you synchronize the recordings with the .log file? Is the zero in the recordings correspond to the zero in the .log?

Francois

Dear Francois,

Thank you for your efforts, that’s exactly what we need. We’ve recently found the zero point - it’s shifted forth for 10 seconds from time of stimulation (“time”). Now we’re trying to figure out how synchronization works. So we’ll inform you, when we comprehend this ourselves. And time unit is one second times ten to the minus four power (1 × 10−4) .

Much thanks,

Kirill

We realised how synchronization works: only stimulation file name (“code”) and time of stimulation (“time”) are needed to import data from .log file to Brainstorm. We synchronize our recordings and .log files (Presentation) by using com-port. Time unit is still one second times ten to the minus four power and that’s confirmed. Presentation doesn’t know when we start our recording and counts first stimulation as a zero point in time. That’s why time of the first stimulation equals zero point. We will be really appreciative, if it’s possible to set first stimulation time by ourselves.

Much thanks,
Kirill

Hi Kirill,

I added some support for the Presentation .log file with the information you gave me.
Update Brainstorm (menu Help > Update Brainstorm), and you should be able to load the .log files in your recordings from the Record tab (menu File > Add events from file)

To change the time origin of all the events, you can select all the categories and use the menu Events > Add time offset.

Let me know how this goes.
Francois

FYI: I updated the reader for the .log files, to support different types of file structures.
http://neuroimage.usc.edu/forums/showthread.php?2845-Importing-Events-from-Logfile

Dear Francois,

Thank you for all your support and feedback, really appreciate it.
Everything is working fine, just like we wanted.

Kirill