Eye Tracking Settings
The EyeTracker Settings window primarily allows the user to configure settings for processing eye signals from an external eye tracker that are received via DataPixx analog inputs. Optionally, it also allows configuration of direct communication with SR Research EyeLink and Pupil Labs eye trackers using TCP/IP protocols.
There are two methods for transmitting eye tracker data from an EyeLink PC to Matlab:
- The first is via the analog output cards installed in all SCNI EyeLink II PCs, which is sent to the Data Translation DT330 breakout board inside the SCNI interface box. This method sends six channels of eye data (X, Y and pupil for each eye) to the DataPixx, TDT and Open Ephys analog inputs.
- The second method utilizes the EyeLinkToolbox components of PsychToolbox to control the EyeLink PC via TCP/IP, recording the eye data digitally on the local machine whilst also reading from the buffer while the experiment is running. Accurate temporal synchronization of eye position data and neural data is achieved via alignment of timestamps send from DataPixx simultaneously to the EyeLink analog card and TDT/ Open Ephys analog input channels.
The Pupil Labs video eye tracking software communicates with Matlab exclusively via TCP/IP using the ZMQ wrapper. Since Pupil Labs eye tracking is currently only used in the immersive VR dome environment of the SCNI, this eye position data can optionally be integrated with head tracking data from the Optitrak system, for online calculation of gaze direction in a world-centered coordinate frame.
