Optomotry hd software

A trained observer-operator recorded the visual acuity of the mice as determined by observing their reflexive head tracking movements (optomotor response) while masked to the cohorts of the mice under examination. This was conducted using a virtual optomotor system (OptoMotry; Cerebral Mechanics, Inc., Lethbridge, Canada) using their custom software (OptoMotry HD software version 2.0.0(4907). The mice were placed on a platform inside a four walled chamber made of computer monitors with screens displaying vertical alternating black and white stripes (gratings), shown under photopic conditions at 100% contrast and with thicknesses (spatial frequencies) ranging from 0.2 to 0.5 cycles per degrees rotating at 12.0 d/s. In mice, optomotor behavioral assays measure the rotation of the head in response to the rotation of these gratings.
Head rotation is driven by oculomotor reflex, which keeps moving images stable on the retina.
The thickness of the gratings corresponds to spatial frequencies (cycles per degree). For example, thin gratings test high spatial frequencies and thick gratings test low spatial frequencies. The highest spatial frequency at which a head rotation could be reliably detected was recorded as the visual acuity of the mouse.