A touchscreen based global motion perception task for mice

- A global motion, random dot kinematogram touchscreen task for freely moving mice.
- Mice reliably learned, and performed hundreds of trials per session.
- Quantitative psychometric curves were reproducible mouse-to-mouse.
- Parameter alterations measured effects of stimulus parameters on motion perception.
- This method can be used to measure higher visual functions in mice.

Global motion perception is a function of higher, or extrastriate, visual system circuitry. These circuits can be engaged in visually driven navigation, a behavior at which mice are adept. However, the properties of global motion perception in mice are unclear. Therefore, we developed a touchscreen-based, two-alternative forced choice (2AFC) task to explore global motion detection in mice using random dot kinematograms (RDK). Performance data was used to compute coherence thresholds for global motion perception. The touchscreen-based task allowed for parallel training and testing with multiple chambers and minimal experimenter intervention with mice performing hundreds of trials per session. Parameters of the random dot kinematograms, including dot size, lifetime, and speed, were tested. Mice learned to discriminate kinematograms whose median motion direction differed by 90 degrees in 7-24 days after a 10-14 day pre-training period. The average coherence threshold (measured at 70% correct) in mice for this task was 22 ± 5%, with a dot diameter of 3.88 mm and speed of 58.2 mm/s. Our results confirm the ability of mice to perform global motion discriminations, and the touchscreen assay provides a flexible, automated, and relatively high throughput method with which to probe complex visual function in mice.

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