08-27-2020, 03:59 PM
Neurobehavioral Systems Presentation -- In the NBS Presentation programming environment the EyeLink API can be accessed via the PresLink extension, which uses Presentation’s general eyetracker extension capabilities to allow interaction with EyeLink systems. This interaction includes:
Installation Instructions:
Testing your installation:
Once the PresLink extension has been registered, you can use the Extension Manager to test the extension and verify that Presentation can communicate with the Host PC. To test the extension, select PresLink in the Registered Extensions box and then click Test Extension.
This will bring up the Eye Tracker Extension Test dialog. You can click the Start button at the top-left followed by the Start button for Tracking, Recording, and for some of the Data sections to verify that Presentation can communicate with the Host PC/eye tracker.
PresLink Templates/Example Projects:
The EyeLink Developers Kit for Windows includes example scripts to illustrate how you can integrate the EyeLink system into your Presentation project. You can find these projects in the Windows Start menu -> All Programs -> SR Research -> EyeLink Sample Experiments -> NBS Presentation directory after you have installed the Eyelink Developers Kit on your system. Note that calls to the EyeLink API can only be interfaced with the Presentation Control Language (PCL) which can be called from the PCL section of your Scenario (SCE) file (as the example projects do) or from a separate PCL file.
Below is a table of contents for what is contained within each of the demos included in the [/i]NBS Presentation[/i] folder, along with a detailed description in the contents.sce file.
PresLink SimplePicture Experiment Walkthrough:
The NBS Presentation folder that contains the example experiments mentioned above also includes a PDF document called Getting Started With Presentation And PresLink. This document contains a detailed walkthrough of the SimplePicture example mentioned above.
EyeLink Data Viewer Messaging Commands and Syntax
Throughout the course of your experiment, in addition to sending messages to the EyeLink data file (i.e., EDF file) that log the timing of events within your task, it's typically a good idea to send special messages that allow integration with Data Viewer. The examples included in the EyeLink Developers Kit illustrate how to send special messages to the EDF to convey important information to Data Viewer, like trial starting/ending times, trial variable values, trial stimulus information, and more. You can find a webinar at the following link that covers the formatting of these messages in detail: You can also find full documentation of the protocol in the Data Viewer User Manual (Help -> Contents) under the section "Protocol for EyeLink Data to Viewer Integration".
Documentation:
Additional documentation can be found in the following resources:
- sending commands to configure and control the eye tracker
- sending event-marking messages to log the times of critical experimental events in the EyeLink data file (EDF file)
- accessing the data from the eye tracker in real-time (e.g., for gaze-contingent experimental designs)
- conveying special information to Data Viewer, including the logging of trial variable information, stimulus presentation information, and more
Installation Instructions:
- Configure your Display PC's network connection to communicate with the EyeLink Host PC.
- Install the latest version of Presentation
- Install the latest version of the EyeLink Developers Kit for Windows
- Register the PresLink Extension within Presentation
- Open Presentation
- Go to the Tools menu -> Extension Manager
- Click Select Extension File.
- Navigate to the C:\Program Files (x86)\SR Research\EyeLink\libs folder and select the PresLink.DLL file
- In the Register As Field, enter PresLink
- Click Register Extension
- Open Presentation
Testing your installation:
Once the PresLink extension has been registered, you can use the Extension Manager to test the extension and verify that Presentation can communicate with the Host PC. To test the extension, select PresLink in the Registered Extensions box and then click Test Extension.
This will bring up the Eye Tracker Extension Test dialog. You can click the Start button at the top-left followed by the Start button for Tracking, Recording, and for some of the Data sections to verify that Presentation can communicate with the Host PC/eye tracker.
PresLink Templates/Example Projects:
The EyeLink Developers Kit for Windows includes example scripts to illustrate how you can integrate the EyeLink system into your Presentation project. You can find these projects in the Windows Start menu -> All Programs -> SR Research -> EyeLink Sample Experiments -> NBS Presentation directory after you have installed the Eyelink Developers Kit on your system. Note that calls to the EyeLink API can only be interfaced with the Presentation Control Language (PCL) which can be called from the PCL section of your Scenario (SCE) file (as the example projects do) or from a separate PCL file.
Below is a table of contents for what is contained within each of the demos included in the [/i]NBS Presentation[/i] folder, along with a detailed description in the contents.sce file.
| Templates | Descriptions |
|---|---|
| SimplePicture | A simple EyeLink integration demo that records eye movements while an image is presented on the screen. |
| SimpleVideo | Simple video demo with EyeLink integration and animated calibration / drift-check/correction targets. In each trial eye movements are recorded while a video stimulus is presented on the screen. |
| Pursuit | A smooth pursuit EyeLink integration demo that records eye movements while a target moves sinusoidally across the screen. |
| MRIDemo | Simple MRI demo with EyeLink integration. 8 trials are presented in 2 blocks of 4 trials each. 500 msec fixation cross is presented, followed by a 7 sec image presentation, followed by a fixation cross for 2500 msec. Each trial consists of 5 pulses (the main pulse is every 5th pulse) of 2 sec each. A block starts with a drift-check followed by presentation of central crosshairs. Eye movements are then recorded while waiting for an MRI trigger (keyboard key 't' in this demo). The stimulus is presented when the trigger is received. Eye movements are recorded throughout an entire block rather than on a trial-by-trial basis. |
| FixWindowFastSamples | EyeLink gaze-contingent demo showing how to retrieve the latest gaze samples online. In each trial central crosshairs are shown until gaze is detected continuously within a central square window for 500 msec or until the space bar is pressed. An image is then presented. |
| GCFastSamples | A simple EyeLink gaze-contingent demo showing how to retrieve fast online SAMPLES. In each trial an image is presented with a red gaze-contingent dot overlaid on top. The dot's location is updated online based on the x, y coordinates of the latest gaze SAMPLE retrieved online. |
| GCLinkEvents | A simple EyeLink gaze-contingent demo showing how to retrieve online EVENTS from a buffer. In each trial an image is presented with a red gaze-contingent dot overlaid on top. The dot's location is updated online based on the end x, y coordinates of each saccade detected. |
PresLink SimplePicture Experiment Walkthrough:
The NBS Presentation folder that contains the example experiments mentioned above also includes a PDF document called Getting Started With Presentation And PresLink. This document contains a detailed walkthrough of the SimplePicture example mentioned above.
EyeLink Data Viewer Messaging Commands and Syntax
Throughout the course of your experiment, in addition to sending messages to the EyeLink data file (i.e., EDF file) that log the timing of events within your task, it's typically a good idea to send special messages that allow integration with Data Viewer. The examples included in the EyeLink Developers Kit illustrate how to send special messages to the EDF to convey important information to Data Viewer, like trial starting/ending times, trial variable values, trial stimulus information, and more. You can find a webinar at the following link that covers the formatting of these messages in detail: You can also find full documentation of the protocol in the Data Viewer User Manual (Help -> Contents) under the section "Protocol for EyeLink Data to Viewer Integration".
Documentation:
Additional documentation can be found in the following resources:
- Documentation for Presentation’s general eye tracker functions can be found in the Presentation User Manual (Help -> Presentation Documentation) under the section “Extension -> Eye Tracker Extension”.
- Documentation for the PresLink commands can be found in the PresLink User Manual (Windows Start menu -> All Programs -> SR Research -> Manuals -> Preslink User Guide).
- A more detailed introduction to PresLink, including a walkthrough of the SimplePicture example is provided in the Getting Started With Presentation And PresLink.pdf document that can be found by going to Windows Start menu -> All Programs -> SR Research -> EyeLink Sample Experiments -> NBS Presentation directory.