Exporting GSR data recorded with Pro Lab - Shimmer3 GSR+

Tobii Pro Lab Shimmer GSR Biometrics

Raw GSR data synchronized with eye tracking data and the stimulus information can be exported in a text format on the Data Export tool in Pro Lab. 

Exporting GSR data

Once we generated the recordings with a Shimmer3 GSR+ device the next step is to do something with the data. To accomplish this:

  1. Go to the Data Export tool in the Analyze module.
  2. Select Galvanic skin response (GSR) column, together with any relevant eye tracking or stimulus information data variable. Make sure to include the Recording timestamp column.
  3. Select the relevant Recordings and/or Time of Interest
  4. Click Export.

The data is saved in a column in a tab-separated values file (.tsv) together with the gaze data, the stimulus, fixations and manually logged events. This data can easily be imported and processed further by Excel, Matlab or Python scripts.

Pro Lab data export file

Each column of the *.tsv output file contains the type of data specified by the name in the top row of the column. All data types are described in the Tobii Pro Lab User Manual, in section 8.5.

Images and videos Start and End events will be reported in the "Event" and "Event value" columns. The GSR data will get its own column in the data export. All rows in a data export file have a recording timestamp value (except for the first row which contains column data type name). The timestamp is shown in milliseconds and starts at 0 at the beginning of each recording. Since all recorded eye gaze data samples have been recorded in a sequence, all eye gaze data points in a recording will have different timestamps.  

Note: some GSR data points may have the same timestamp as eye gaze data points, while others may have timestamps between two eye gaze data point timestamps. Since, the gaze data points and the GSR data have their own rows in the export file, the relationship between the number of rows and time is not always linear - e.g. when the GSR data point has the same timestamp as the the gaze data point it will still originate 2 rows. 

In the image above we can also observe that for every one eye tracker timestamp you have two GSR timestamps, This is due to the fact that the eye tracker and the GSR device have different sampling rates (60 Hz and 120Hz respectively).

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