Facilities and Equipment at the Center for Visual Neuroscience

Two 168-channel ActiveTwo EEG recording and analysis system from BioSemi, Inc., as well as a 64-channel EEG system from Neuroscan, Inc.
Custom-designed by Dr. Teder-Sälejärvi, these computer-controlled tactile stimulators rely on gravity to return to their default positions; the driving elements are simple induction coils. This stimulator enables the investigation of the electrophysiological correlates of tactile perception and attention, such as the distribution of spatial attention across the fingers of the hand.
The Skalar IRIS IR Light Eye Tracker is a limbus tracker designed specifically for oculomotor research.
Two Macintosh-based psychophysical workstations with high temporal-frequency video pipelines optimized for displaying stereo stimuli at refresh rates of 200Hz or more. The Stereographics ZScreen is an active circular-polarization filter that, used in conjunction with passive circularly polarized glasses, delivers frame-interleaved images separately to the left and right eyes, thus enabling studies of stereoscopic depth perception.
The Canon EOS-1Ds is an extra high-resolution professional digital camera featuring a full-frame 35mm CMOS sensor with 11.1 million effective pixels.
The AuSIM3D system by AuSIM, Inc. is an integrated sound measurement and delivery system. Complex 3D sound environments can be rendered in real-time based on individualized head related transfer functions; 3D soundscapes can be integrated with immersive visual VR environments to allow precise stimulus control for the study of auditory-visual multisensory integration.
Several psychophysical and EEG (Neuroscan, Inc.) laboratories are housed in Industrial Acoustic Company, Inc. anechoic chambers.
Three ViSaGe high-resolution 14-bit visual display systems (Cambridge Research Systems, Ltd.) designed for spatial and color vision research.
Two ASL Model 504 remote video eyetrackers, designed for use in situations where the stimulus presented to the subject is restricted to a single surface such as a computer or video monitor, and where head-mounted optics are not desirable. The system allows the subject approximately one square foot of head movement which eliminates the need for head restraint.
NIER (Natural Illumination Environment Replicator). This device is used to reproduce illumination environments, which were captured outdoors or at any remote location. The Replicator can reproduce these environments in a controlled way, for in-lab studies. We will be using the Replicator to hold complex illumination conditions constant while varying other scene parameters. We will also use the Replicator to vary the illumination environment in a controlled fashion. The Replicator is being constructed at NDSU with the help of the Electrical & Computer Engineering and Mechanical Engineering Departments.
The Minolta VIVID 9i is a high precision 3D laser scanner. Since the process of visual perception is one of reconstructing models of 3D scenes from 2D images, we use this device to measure depth relationships in actual 3D scenes.
The nVisor SX (nVis, Inc.) is a state-of-the-art head-mounted display with high resolution (1280x1024) and wide field of view (60 degrees). Camera-based optical position tracking (WorldViz, Inc.) allows the construction of virtual environments for psychophysical research.
Two ETSLindgren Four-Shield EEG recording chambers (24 Ounce Copper, 24 Gauge Silicon Steel). Each chamber measures 8' W x 10' L x 8'9" H. Magnetic Field Attenuation (60 Hz, 30 dB). Electric Field Attenuation (14 kHz, 120 dB).
DriveSafety’s driving simulation system. DriveSafety’s DS-600c (full-size, 180°, 240°, 300°)
Our EEG data transfer, analysis and storage system is based on a Dell 2850 Poweredge server (Red Hat Enterprise ES4 OS) and attached Dell EMC CX300 1.5TB disk storage array. Data backup is provided by a Dell Powervault 132T robotic tape library. A Summit 400-24D gigabit switch supports local intranet with gigabit data transfer rates. Our computational modeling cluster consists of 8 networked Intel Pentium 4 hyperthreaded 3.0 GHz computers running Red Hat Enterprise ES4 OS. This cluster supports applications using Grid Mathematica, Matlab distributed computing engine and Alias Mental Ray Renderer for Maya.
The BrightSide Technologies, Inc. DR-37P 37" high-dynamic range display monitor, with a peak luminance in excess of 3,000 cd/m² and a contrast ratio exceeding 200,000:1, allows vision researchers at the Center for Visual Neuroscience to present images with truly “natural” dynamics.
A custom-designed (Dr. Teder-Sälejärvi) 55-channel free-field stimulator to investigate brain responses to audio-visual signals. Speakers and LEDs at each of the 55 locations have their own microprocessor and memory and can deliver up to six sounds and 255 different light patterns via RGB LEDs. This unique computer-controlled device is an essential prerequisite to realistically simulate moving “objects” in free-field.
The Konica-Minolta luminance meter (LS-110) is a highly sensitive photometer used for measuring the luminance of light sources or reflective surfaces.
The VariSpec™ Liquid Crystal Tunable Filter (LCTF) is a high-quality interference filter, but the wavelengths of the light it transmits are electronically controllable, providing rapid, vibrationless selection of any wavelength in the visible and near-infrared tuning ranges. Mounted in front of a high-intensity light source the VariSpec serves as a monochromator; mounted in front of the Canon EOS-1Ds digital camera it allows the acquisition of hyperspectral images.
Two head-mounted high-speed video eyetrackers (Eyelink II) allow unrestricted head movement and the collection of point-of-regard data from human subjects during experiments on visual attention and perception.
A Polhemus PATRIOT digitizer localizes the 3D spatial (X,Y,Z) coordinates of the BioSemi ActiveTwo electrodes with pinpoint accuracy to create a 3-D map of electrode locations, enabling the scalp topography of electrical signals to be mapped with great accuracy and precision.
The VisionStation (Elumens, Inc.) is a large-format spherical projection system; the projected image subtends the entire field of view, enabling studies of very wide-range visual field interactions, as well as the study of peripheral visual processing.
These miniature computer-controlled tactile stimulators have the advantage that they do not rely on gravity to return to their default position. With these devices, Dr. Teder-Sälejärvi will investigate how the brain maps our extra-personal space and how proprioceptive information is used (with or without vision) to encode the relative coordinates of our extremities in free-field.
A PR-650 SpectraColorimeter (PhotoResearch, Inc.) enables the precise calibration of visual display devices that modern research in color vision demands.