Knowledge Base

Examples of Nesting Over a Free Interval

Example 1: Analyze the First 20 cm of Swim Path in a Water Maze

Aim

Suppose you want to analyze the movement of the subject in the initial swim path, say in the first 20 cm. A Data profile with Free interval "From track start to Total distance moved 20 cm" is defined. In the Analysis profile you can then for example define the heading angle of the subject, which will be calculated for that interval.

Solution

In the Data profile, under Nesting choose Free interval, with:

• Start criterion: Track start.
• Stop criterion: Dependent variable Distance moved, Statistic Total, is >= 20 cm.

Note that the Total Distance moved is unlikely to be exactly 20 cm at a given sample time; for this reason, the end criterion says ">= 20 cm".

Next, in the Analysis profile choose the variable you want to calculate, for example Heading to point, or Turn angle. Then choose Analysis > Results > Statistics and Charts.

See also:

• Analysis advisor: Analysis in relation to the path

Example 2: Analyze the Time up to When the Subject Has Explored an Object for 30 Seconds

Aim

In a novel object experiment, the trial lasts for example 5 minutes. Subjects often differ in the amount of time spent exploring the objects. The researcher wants to analyze the same exploration time across subjects, for the object labeled as zone "Familiar object".

Solution

In the Data profile, under Nesting choose Free interval, with:

• Start criterion: Track start.
• Stop criterion: Dependent variable In zone, Statistic Cumulative duration, is >= 30 s. In zone is a dependent variable defined for the zone "Familiar object" and the body point "nose-point".

Next, in the Analysis profile choose the variable you want to calculate, for example In zone, to calculate the number of exploration events in the 30 s of exploration time. Then choose Analysis > Results > Statistics and Charts.

See also:

• Zone visits (entries and time spent)
• Other analyses with zones

Example 3: Compare Two Intervals, 5-s Before vs. 5-s After a Stimulus

Aim

In a DanioVision experiment, a white light stimulus is presented to zebrafish larvae. The researcher wants to compare the movement parameters of the animals in the 5 s before the onset of the stimulus, with those in the 5 s thereafter.

Solution

In the Data profile, create two Free intervals based on Trial Control.

The first free interval goes from 5 seconds before "Action: Light on" to 0 s after start event (which is "Action: Light on").

The second free interval goes from 0 s before "Action: Light on" to 5 s after start event (which is "Action: Light on").

Connect the two Nest boxes to different Result boxes. To create an additional Result box, under Common elements click the button next to Result. See Multiple selections in a data profile.

Next, in the Analysis profile choose the variable you want to calculate, for example Movement, to quantify movement in the selected periods of time. Then choose Analysis > Results > Statistics and Charts.

Nesting Over a Multi Condition

Aim

To pick out the track segments corresponding to a Multi condition. To get an idea of what a Multi condition is, see Multi condition in the Analysis profile.

You can also define complex selections by combining two or more Nesting boxes. See Multiple nesting criteria. However, there are limitations. For example, you cannot select the points when "Distance to zone was less than 10 cm" using a Nest box. However, you can do that by creating a Multi condition.

Example: Select all the points in the track when (a) the subject's Body elongation state was Stretched and (b) its Distance from the zone Object was less than 10 cm. Then, create a heatmap.

Procedure

1. In the Data Profile, under Nesting click the button next to Multi condition.
2. In the Multi Condition window, specify the single conditions that define the Multi condition.
3. Combine the conditions with either All conditions are true (AND logic) or Any condition is true (OR logic). For details, see Dependent Variables in Detail > Multi condition.
4. Click OK. Insert the resulting Nest box in the appropriate position between the Start and the Result box. See How to Select Track Segments.

Nesting vs. Nesting Over Subjects

If your trials contain multiple subjects and you want to analyze one subject in Multi condition based on the behavior of another subject, click Multi condition under Nesting over Subjects. See Nesting vs. Nesting over subjects.

Notes

• Note the difference:
  • You define a Multi condition in the Data Profile when you want to analyze any dependent variable within the resulting track segment. For example, to calculate the average velocity of the subject when a Multi condition is true.
  • You define a Multi condition in the Analysis Profile when you want to analyze the interval itself. For example, when you want to know the total duration of the Multi condition being true. However, you won't get, for example, the average velocity in the resulting track segment. See Free interval in the Analysis profile.

Nesting Over External Data

Aim

To pick out the track segments and the associated external data corresponding to a specific range of values in the external data signal.

Example: Select all intervals when heart rate was above a certain value. Then analyze distance moved, velocity, and movement.

Procedure

1. In the Data profile, under Nesting, click the Add button next to [data set name] state.
2. Define the state variable. For details, see External data - state in the Analysis profile.
3. Click OK. Proceed with step 4 on How to Select Track Segments.

Notes

• The track segments are based on the values of external data calculated on the re-sampled signal, not the original (imported) signal.
• If you have chosen the variable under Nesting over Subjects, the Actors tab is also available. Select the subjects whose state define the nesting intervals. If you select two or more subjects, select:
  • Any selected subject. To analyze the time that at least one subject was in that state.
  • All selected subjects. To analyze the time that all subjects were in that state simultaneously.

Nesting Over Subjects

See also:

• Nesting vs. Nesting over subjects
• Nesting over subjects
• How to Select Track Segments