The visual stimulation / oculomotor data collection environment is based on the complementarity of two high-level equipment : the PROPixx video projector from VPIxx Technologies and the EyeLink 1000 Eye-Tracking system from SR-Research.
The PROPixx projector
The PROPixx is a very high performance video projector specifically designed for research in psychophysics of vision. Based on a high brightness DLP LED technology, the PROPixx provides a particularly wide range of colors, a large bit depth and high frequency colour stimulation. Its characteristics are as follows:
- Native 16:9 FullHD (1920×1080) Matrix
- Resolutions (spatial and temporal) ;
- 120 Hz in FullHD RGB
- 480 Hz (960×540 RGB)
- 1440 Hz (960×540 Grey)
- Native contrast 2000:1
- Full API (Python)
- Specific optical zoom
The long-focal optics have been specifically calibrated to optimize the field of view at the projection screen behind the magnet tunnel.
The PROPixx controller allows to duplicate the image to the LED monitor located on the desk and also allows some advanced synchronization operations
The EyeLink-1000 System
Distributed by SR-Research, the EyeLink 1000 system is a reference in the field of oculomotor data recording.
The EyeLink 1000 System consists of the following components:
- Outside the MRI room
- A control PC placed in the stimulation room
- An ultra-fast “smartcam” type camera (1000 fps) connected by an Ethernet link to the control PC.
- Two specific power supplies which are filtered at the Faraday Cage’s Filter Plate (PPf).
- Inside the MRI room
- A near-infrared light source to illuminate the subject’s eyes
- A remote CCD sensor identical to the one integrated in the smartcam.
The remote sensor is connected to the camera via an optical fiber passing through one of the Faraday Cage Wave Guides.
The light source and the sensor are powered by the two filtered sources.
The EyeLing system is permanently positioned on the screen support behind the magnet tunnel and detached from the magnet. Placed correctly in its marks on the ground, this support ensures a visual field (on a 1080 x 1080 square area) of 20°, outside the area covered by the EyeLink elements. In this configuration, the settings of the Eye Tracking system are minimal…