Knowledge Base

Detect the subject

1. Choose Setup > Detection Settings. Open the default Detection Settings 1.
2. If you work with video files, under Video click Select Video and choose a video file. Play the video up to when the subject appears. If you work with cameras, release the animal in the arena.
3. Click Automated Setup. Choose the type of subject you test, and click Next.
4. Wait until the subject is free from contact with objects or walls and walks with a normal posture. When ready, draw a rectangle around the subject. Do this for all subjects in the arena. tip For rodents, try to leave the tail out of the rectangle. In all other cases, include the animal's tail.
5. If the subject's body is well detected, click Yes. Otherwise, try moving the Finetune slider and check if the yellow blob covers the entire animal's body (excluding the tail). If detection does not improve, try again a few times using another image from the video. If this does not help, click No and click Advanced. For details, see Configure Detection Settings > Advanced Setup in the EthoVision XT Help.

Tracking the nose and tail-base

In all cases, make sure that the body of the animal is well detected. Detect the subject If you use the Deep learning detection technique with one subject per arena, under Method click Define and select a box around the subject. Make sure that there is some space around the subject's body, like in this example.

Notes

Check that the subject is well detected in all parts of the arena. In the Detection Performance pane, check that the proportion of samples where the subject is not found is acceptable (for example less than 1%). If you selected Activity analysis in the Experiment Settings to detect freezing, click Activity. Adjust the settings until most of the purple pixels only appear when the animal moves. When the animal freezes, the number of purple pixels should be minimized. Prepare a list of trials (optional)

Prepare a list of trials (optional)

the trial list

In EthoVision XT, a Trial is an uninterrupted recording session. The Trial List is a table listing the trials planned for an experiment. When you create a new experiment, a few planned trials are already present.

To add more trials

1. Choose Setup > Trial List. Click the Add Trials button.
2. Type the number of trials you plan to carry out and click OK.
3. For each row: Specify the independent variables (optional; see the next page). Specify which video file you want to use (when tracking from video files). Select Arena Settings, Trial Control Settings, and Detection Settings (optional). If those columns are not present in the Trial list, click the Show/Hide button, click Variables and select them.

Notes

Planning your trials in advance also allows you to acquire trials in batch mode. See Trial List in the EthoVision XT Help. Figure 2 Planning ten trials in the Trial List. Prepare a list of trials (optional)

independent variables

What are Independent variables?

Independent variables are either simple descriptive categories (such as the genotype or age of your rats or mice), or conditions manipulated by the researcher (such as the substance being tested and the dosage). You can use independent variables to create analysis groups or filter data. For example: Compare tracks of treated subjects with tracks of control subjects. Only analyze subjects of a specific age class. note If you created a template experiment, one or more independent variables have been predefined in your Trial List. For instance, Animal ID and Treatment.

To define an independent variable

1. Choose Setup > Trial List.
2. Click the Add Variable button. A new column appears on the right of the table.
3. Specify the Label (for example: Dose), Description, Type (for example, Text or Numerical), Format, Predefined values (for example, 0.01, 0.02 etc. mg/kg), and Scope (whether the values of the variable differ between subjects within the same arena, between arenas within the same trial, or between trials). Acquire the data

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Source: EthoVision XT 18 - Quick Start Guide