Knowledge Base

Nest

Definition

A discrete (state event) variable that is scored when the subject is in contact with two or more subjects. All those subjects do not move.

Note that the variable Nest has nothing to do with nest-building behavior.

Calculation

EthoVision XT considers the events of type Contact stored in the Live Mouse Tracker database, which overlap with the events of type Stopped. That means that Nest includes only instances when the focal subject is in contact with other subjects, like in Group, with the additional condition that none of those subjects moves.

Finally, instances of Nest shorter than two samples are removed and adjacent instances up to three samples apart are joined to form one instance.

Contrary to Group, EthoVision XT does not split the results based on the identity of the subjects forming a Nest.

How to Specify Nest

1. Open an Analysis profile and in the Dependent Variables panel, under Live Mouse Tracker, click the Add button next to Nest.
2. Specify the Nest size.
3. Complete the procedure to add the variable to the Analysis profile. See Calculate statistics: procedure.
4. If you wish to have the results for all nest sizes in one table, repeat the steps above to add more Nest variables, one for each size.

Example

Subject A (red dot), B (light green) and D (dark green) are forming a nest. Subject C (orange dot) walks around and is therefore not part of the nest.

In the Trial Statistics, Frequency is the number of instances of Nest (color bars on the time line as in the figure above) and Cumulative Duration is the sum of the duration of all the instances in the selected trial (or interval).

Applications

You can use Nest to quantify the tendency of subjects to huddle together and form groups. Nest occurs especially in the sleep (light) phase.

See also

• Group
• Dependent variables for Live Mouse Tracker

Nose Contact

Definition

A discrete (state event) variable that is scored when the focal subject's nose is near the nose point or the tail-base point of another subject.

Calculation

• Nose-nose contact is scored when the distance between the nose-point of the focal subject is at less than 15 pixels (26 mm for Live Mouse Tracker arenas) from the nose-point of another subject.
• Nose-anogenital contact is scored when the distance between the nose-point of the focal subject is at less than 15 pixels (26 mm for Live Mouse Tracker arenas) from the tail-base point of another subject.

How to Specify Nose Contact

1. Open an Analysis profile and in the Dependent Variables panel, under Live Mouse Tracker, click the Add button next to Nose contact.
2. Under Calculate Statistics for, select Nose-nose contact, Nose-anogenital contact, or both.
3. Click the Receivers tab. Under Select, choose the subjects that the focal subject was in nose contact with. If you select two or more subjects, select one of the available options from the list:
   • All selected subjects: Nose contact is scored when the focal subject was in contact with all the subjects selected above.
   • Any selected subject: Nose contact is scored when the focal subject was in contact with any of the subjects selected above.
   • Each subject: Nose contact is scored when the focal subject was in contact with one of the subjects selected above. The results are displayed for each Receiver.
4. Complete the procedure to add the variable to the Analysis profile. See Calculate statistics: procedure.

Example

A Nose contact variable has been defined with both options Nose-nose contact and Nose-anogenital contact selected. In the current video image, Subject A (red dot) is in nose contact with Subject D (dark green dot).

In the Trial Statistics results table, with the default layout, the results of Nose contact are shown per subject (on the rows). The columns vary depending on what you chose in the Receivers tab:

• If you chose Each subject, the columns contain the statistics of Nose contact with specific subjects (for example, Nose-nose contact / A to D).
• If you chose All selected subjects or Any selected subject, a column Nose-nose (or Nose-anogenital) / All of A, B, C, D or Nose-nose (or Nose-anogenital) / Any of A, B, C, D contains cumulative statistics of Nose contact when the subject was in contact with all cage mates simultaneously or with any of them, respectively, depending on which option you chose.

Notes

• For this variable, Live Mouse Tracker takes the distance between the body points on the X,Y plane, and ignores their Z coordinates.
• In the Analysis profile under Social, you find Body contact. This is a variable that quantifies the level of generic body contact between subjects.

See also

• Nose contact sequence
• Social Behavior > Body contact
• Dependent variables for Live Mouse Tracker

Nose Contact Sequence

Definition

A discrete (state event) variable that is scored from an instance of nose contact of one type to the following nose contact of opposite type, both performed by the focal subject.

In other words:

• From an instance of Nose-nose contact to the next instance of Nose-anogenital contact. Or
• From an instance of Nose-anogenital contact to the next instance of Nose-nose contact.

See also Nose contact.

Calculation

1. EthoVision XT selects all instances of type Nose-nose contact or Nose-anogenital contact (depending on what is chosen in the settings), and longer than 10 video frames (0.33 s for a video of 30 fps).
2. EthoVision XT selects all the instances of type of Nose-contact other than that selected in the previous step, and longer than 10 video frames (0.33 s).
3. If the second Nose-contact occurs within 60 video frames (2 seconds, for a video of 30 fps) from the end of the first one, a Nose contact sequence is found.

How to Specify Nose Contact Sequence

1. Open an Analysis profile and in the Dependent Variables panel, under Live Mouse Tracker, click the Add button next to Nose contact sequence.
2. Under Calculate Statistics for, select Nose-nose to Nose-anogenital, Nose-anogenital to Nose-nose, or both.
3. Complete the procedure to add the variable to the Analysis profile. See Calculate statistics: procedure.

Example

The following example shows a sequence of type Nose-nose contact to Nose-anogenital contact of Subject A directed to Subject B. The position and orientation of the subjects at the beginning and at the end of the sequence are shown. Triangles represent the nose points and squares represent the tail-base points.

See also

• Nose contact
• Dependent variables for Live Mouse Tracker
• Social > Body contact

Source: EthoVision XT 19 Help, Noldus Information Technology