Aim
You can use the following variables to analyze basic events in the Live Mouse Tracker datasets. For example, Contact events.
Approach
Definition and calculation
A discrete (state event) variable that is scored when the focal subject reduces its distance to another subject. Approach is based on the approach events detected by Live Mouse Tracker and imported in EthoVision XT. Approach events occur when:
▪The speed of the focal subject is greater than the speed of the other subject.
▪The distance between the two subjects at the sample k-3, that is, three video frames before the current one k, is greater than the distance at the sample k+3, that is, three video frames after the current one k.
Detection occurs during data acquisition, therefore outside EthoVision XT, and its settings cannot be modified in EthoVision XT.
A discrete (state event) variable that is scored when the focal subject is in contact with another subject. Contact is based on the contact events detected by Live Mouse Tracker and imported in EthoVision XT. Contact events occur when the distance between the detected contours of the animals gets below a fixed threshold. Detection occurs during data acquisition, therefore outside EthoVision XT, and its settings cannot be modified in EthoVision XT. For more information, please see the Live Mouse Tracker documentation.
note The dependent variable Body contact under Social behavior in the Analysis profile won’t give results with Live Mouse Tracker data, because Body contact can only be based on EthoVision XT’s own track data.
Look
Look is a state event variable with possible values Look_up and Look_down.
▪Look_down: The subject’s head is pointing downward, for example when sniffing the substrate.
▪Look_up: The subject’s head is pointing upward, for example when rearing at the wall.
Rearing
Rearing is a discrete (state event) variable with two possible values, Rearing and Not rearing. For how it is calculated, see Rear (you can find this variable under Live Mouse tracker).
The difference between Rearing and Rear is that Rearing includes all rearing events, instead of splitting them into two categories, Rear in contact and Rear alone.
Speed
Speed is imported into EthoVision XT and shown in the Analysis profile under Raw Live Mouse Tracker data, but it is not used as an output variable.
Stop
Stop is based on the stop events detected by Live Mouse Tracker and imported in EthoVision XT. Stop events occur when the speed of the subject gets below a fixed threshold (see Live Mouse Tracker > Stop). Detection of stop events occurs during data acquisition, therefore outside EthoVision XT, and its settings cannot be modified in EthoVision XT.
tip To analyze stop events when the subject is in contact with its cage mates, see Stop under Live Mouse Tracker data.
How to specify Raw Live Mouse Tracker data
1.Open an Analysis profile and in the Dependent Variables panel, under Raw Live Mouse Tracker data, click the Add button next to a category.
2.Under Calculate statistics for, select the options you require.
3.If the Receivers tab is available, there you can specify which subject the behavior is directed to. Keep all subjects selected for an overview of all the events directed to any individual (A, B, etc.).
4.Complete the procedure to add the variable to the Analysis profile. See Calculate statistics: procedure
Notes
▪You can also raw Live Mouse Tracker data within JavaScript code to create custom analysis variables. For this purpose, use the GetBehaviorEvent function. See Commands and functions for JavaScript variables
▪Raw Live Mouse Tracker data are not affected by track smoothing. This is because the data are stored during acquisition, and not calculated after import in EthoVision XT. For example, no matter whether you apply Lowess smoothing, the statistics of Contact do not change. On the contrary, Live Mouse Tracker analysis variables are affected by track smoothing, just like any dependent variable in EthoVision XT.
See also
▪Dependent variables for Live Mouse Tracker