Cutaway View of Apparatus:
Rodents stand on an elevated platform in the epicenter of an arena surrounded by computer monitors, and a camera images the behavior of the animal from above.
A cylinder comprised of a sine wave grating is drawn in 3D coordinate space and rotates around the animal. Animals track the grating with reflexive head and neck movements.
A cursor placed on the forehead centers in real time the rotation of the cylinder at the animal’s viewing position, thereby “clamping” the effective spatial frequency of the grating.
OptoMotry© enables the rapid screening of functional vision using the opto-kinetic tracking (OKT) response. Spatial frequency thresholds can be measured by systematically increasing the spatial frequency of the grating at 100% contrast until animals no longer track. A contrast sensitivity function can be generated by identifying the minimum contrast that generates tracking, over a range of spatial frequencies. Single thresholds can be obtained in a few minutes in animals with no previous exposure to the task, and measurements can be repeated regularly. System calibration, data logging, and an array of psychophysical testing methodologies are also managed by the software.