Nesting over subjects

Aim

To analyze the track segments of a subject based on the behavior of a specific subject or combination of subjects, called Actors.

This option is only available if you track two or more subjects simultaneously in the same arena.

Prerequisites

Procedure

1.In the Data profile, choose the variable under Nesting over Subjects.

2.Click the Actors tab of the nesting window. See also How to select track segments

 

3.Select the actors of the behavior defining the interval. Select the subject that should show the behavior of interest. If you select two or more subjects in the Actors tab, select one of the two options from the list immediately below the Subjects box:

▪All selected subjects: To analyze the samples when all the actors show that behavior simultaneously.

▪Any selected subject: To analyze the samples when at least one actor shows that behavior.

 

4.If the Actors tab also contains the Body points options, select one or more body points of the subjects selected above.

5.For the dependent variables of social interaction, a Receivers tab is also available. Receivers are the subjects towards which the behavior of the Actor is directed. For example:

▪To analyze when Subject 2 is moving to Subject 1, Subject 2 is the Actor and Subject 2 is the Receiver.

▪To analyze when Subject 1 is in proximity of Subject 2, Subject 1 is the Actor and Subject 2 is the Receiver.

Click the Receivers tab and select the subjects that you want to define Receivers (see an example below).

6.Click OK. Proceed with step 4 in How to select track segments.

important Be careful when selecting the same subject under Actors and Receivers. In such case you may also get unwanted selections, for example Subject 1's nose point (Actor) In proximity of Subject 1's tail base (Receiver). The resulting selection has little meaning.

examples

▪Social interactions. You want to analyze the time that the nose-point of Subject 1 was in proximity of the tail-base point of Subject 2 (ano-genital sniffing).

Solution: Subject 1 is Actor, Subject 2 is Receiver.

▪Under Nesting over Subjects, click the button next to Proximity.

▪In the Actors tab select Subject 1 and deselect Subject 2. Under Body points, select Nose-point only.

▪In the Receivers tab select Subject 2 and deselect Subject 1. Under Body points, select Tail-base point only.

If you want to select the time that the nose point of Subject 1 was in proximity of the tail-base point of Subject 2, or vice versa, create two nesting boxes, one that specifies Subject 1's nose in proximity of Subject 2's tail base, and the other that specifies Subject 2's nose in proximity of Subject 1's tail base. Next, combine the two boxes with OR logic (see Basic rules for combining selection boxes).

▪One Actor, no Receivers. You want to select the track segments when Subject 2 was moving, and quantify the distance moved by other subjects in that period of time.

Solution: Subject 2 is the Actor. Under Nesting over Subjects, click the button next to Movement.

▪In the Actors tab select Subject 2 and deselect the other subjects.

▪In the Analysis profile, select Distance moved. The statistics results refer to each subject in the specified interval.