Knowledge Base

Split a Multi-Day Test in Multiple Trials

Aim

To acquire trials longer than the maximum duration that is tested at Noldus. See Cameras Supported by EthoVision XT > Resolution, Frame Rate, and Maximum Trial Duration.

Procedure

1. In the Trial Control Settings, remove the condition immediately before the Start Track action box.
2. In the Trial Control Settings, set the maximum trial duration. For example, 24 hours. See Control the End of Tracking. Set this time to a little less than 24 hours, for example 1439 min (= 24 h minus 1 min). The remaining minute is used as the inter-trial interval (see below). You can also choose a shorter inter-trial interval if you like.
3. Choose Setup > Trial List. Add a number of trials that cover the total duration of the test for the subject.
   • Example 1: One arena. Each subject is tested over five days. Therefore, add five trials for that subject.
   • Example 2: Subjects in four PhenoTypers (arenas) are tested over five days. Add five trials. Each trial contains data of one day and the four arenas.
   Only add the trials for the current subject(s), not for the subjects that come next in the protocol. Because you will use the series of trials with a short inter-trial interval, in most cases you will not have time to clean the cages and release the next subject. Add a variable "Subject ID" to the Trial List, and enter the ID of the subjects to be tested so you know which trials refer to which subject.
4. Choose Acquisition > Open Acquisition. Under Method, select Track All Planned Trials with an Inter-Trial Interval of 1 minute. This ensures that EthoVision XT has the time to save the data. If you want to use a shorter time, test it beforehand.
5. Acquire the data.
6. In step 3, add the trials for the next subject(s), and repeat the procedure.
7. In the Data profile, group the trials based on the subject ID. This way you can analyze a multi-trial test as one trial. See Define Groups of Tracks.

Examples of Start-Stop Trial Rules

Start/Stop the Trial in the Morris Water Maze Test

Aim 1: Stop Tracking When the Animal Has Found the Platform

1. In the Arena Settings, make sure that the platform has been defined as a zone.
2. In the Trial Control Settings, delete the Time condition before the Stop Track box.
3. Define an In Zone condition. See also Stop Tracking Based on the Behavior of the Subject. If you want the program to stop recording as soon as the animal is over the platform, select Frequency as Statistic and choose >= 1. Click Settings and select the platform zone. See details about the variable In Zone. Sometimes the animal swims over the platform but does not stop there. In such cases the program would stop recording while the animal has not found the platform. Instead of selecting Frequency, choose Current Duration and the minimum time the animal must stay on the platform (for example, 3 s) without interruption. Click Settings and select the platform zone.

Aim 2: Stop Tracking When the Rat Has Found the Platform or Has Been Swimming for 60 Seconds

The Arena Settings and the condition "the rat has found the platform" are similar to those in the example above. The condition "rat swimming for 60 s" can be translated to "time from start tracking >= 60 s."

The track stops when either condition is met. The two conditions are combined with OR logic. See also Operators. This solution results in tracks of different duration: less than 60 s for the animals that found the platform, and 60 s for the others.

With the Start-Stop Trial rule described below, the trial stops when the subject has been in the platform zone for at least 3 s without break, or the time since the start of tracking is 60 s.

• A. In Zone condition that specifies that the subject must be over the Platform zone for at least 3 seconds. Select Current Duration >= 3s.
• B. Time condition that specifies a time of 60 s since the track started.
• C. "Any" operator box.

Start the Trial in the Social Interaction Test

Aim: Start Tracking When All Subjects Have Been Released in the Arena

1. Click the Settings button in the second box (Condition - In Zone).
2. Click Settings and then the Actors tab.
3. Select all the subjects that need to be in the arena at the time of start.
4. Choose All Selected Subjects below the subject list.

Stop the Trial in the Eight-Arm Radial Maze Test

Aim: Stop Tracking When the Subject Has Been in Four Arms Within 10 Minutes

This can be done by combining eight conditions specifying that the animal must be in each arm, with at least four conditions being met regardless of which arms the animal visits.

1. Create an In Zone condition and specify that the Frequency for Arm 1 must be >= 1, meaning the animal must have visited Arm 1 at least once. Do the same for each of the other arms.
2. Connect the resulting eight condition boxes in parallel using the N of All operator. See Operators.
3. Set the maximum trial duration to 10 minutes to stop tracking in the case the animal fails to visit four arms in the meantime. See To Set a Maximum Duration for Your Trials.

The Trial Control sequence for an eight-arm radial maze works as follows: the trial must stop when the animal has visited four of the arms at least once. Condition boxes 1 through 8 represent In Zone conditions for Arm 1 through Arm 8 respectively. A condition is met when the Frequency of In Zone for that arm is greater than or equal to 1. An operator box checks that at least four of the eight conditions are met. When four conditions are met, the Stop Track box is triggered and the trial is stopped.

See Also

• Operators