Knowledge Base

Analyzing Track Segments in EthoVision XT

Result Boxes and Filtered Data

The two Result boxes receive the data filtered according to the independent variable Treatment Level. Result 1 receives five tracks filtered with Treatment Level = Control. Result 2 receives other five tracks filtered with Treatment Level = Treated.

Tip: The name of the Result box is shown in the results (statistics and track plots), so it is good to give a name that reminds you from which data selection that result comes from. Click Settings in a Result box and rename it. For example, rename Result 1 to Control Group.

View the Results for Groups of Tracks

Prerequisite

You have defined one or more groups of tracks.

To View the Results for Groups of Tracks

1. Create a new Analysis profile and choose the dependent variables (for example, Distance Moved).
2. In the Experiment Explorer, under Results, choose the option you require (Calculate Statistics, Heatmaps, etc.).

In the analysis results, you can see which output is produced by which Result box. Look up the Result header. For example, in the Statistics & Charts screen, click Group Statistics and Charts. In the Heatmaps screen, click Group Mean and then click the Plot Heatmaps button.

Analyze Track Segments

Main Topics and Tasks

• Analyze Track Segments: Main Concepts
• Nesting over Time
• Nesting Using Zones
• Nesting over Behavioral States
• Nesting over a Trial Control State
• Nesting over a Free Interval
• Nesting over a Multi Condition
• Nesting over External Data
• Nesting over Subjects
• Results per Time Bin

Analyze Track Segments: Main Concepts

Analyzing Track Segments

In EthoVision XT you can pick out segments of tracks specified by time intervals or the behavior of the subject. To do so, use the Nesting function in the Data profile. When Nesting is activated, analysis is carried out on the samples within those track segments, and the corresponding video and external (physiological) data. The track segments outside the selection are not included in the analysis.

A track is represented by samples on a time line. For example, a mouse entering a zone partway through the track, then sniffing air towards the end. The samples selected for analysis differ depending on whether you are nesting over a zone, over time (for example, the first half of the track), or over a behavior (for example, sniffing).

An Important Difference

Selecting a variable in the Data profile is not the same as selecting the same variable in the Analysis profile. For example:

• When you choose In Zone under Nesting in the Data profile, you select the samples when the animal was in a zone. Then, in the Analysis profile you choose a dependent variable, like Velocity. As a result, EthoVision XT calculates the velocity of the subject when it was in the zone.
• When you choose In Zone under Location in the Analysis profile, EthoVision XT calculates statistics for the variable In Zone, for example, the time spent in a zone, or the number of zone entries, but not the velocity of the subject when it was in that zone.

Nesting Options

• Nesting over time — to analyze a time interval defined by a Start time and a Stop time. For example, analyze the first 15 minutes of each track.
• Nesting over zones — to analyze the track segments when one or more subjects are within a zone or a combination of zones. For example, analyze the behavior of the mouse when its nose point was in a zone defined around the novel object.
• Nesting over behavioral states — to analyze the track segments corresponding to the state of one or more subjects (for example, Movement or Grooming). This option includes manually-scored behaviors and behaviors recognized automatically. For example, analyze all the samples collected when the animal's body was stretched, or analyze the locations where the animal was sniffing.
• Nesting over trial control states — to analyze the track segments corresponding to the time between two events of Trial Control. For example, analyze the time from when the cue light switched on to when the mouse consumed the food item delivered.
• Nesting over subjects — to analyze the track segments based on the behavior of another subject. This is available when your arena contains multiple subjects, such as in a social interaction test. For example, analyze the track segments of Subject 1 when Subject 2 was in proximity of Subject 1.

Notes

• Track segments defined with Nesting are left-closed [A, B). That is, the start sample A, not the stop sample B, is included in the analysis.
• To analyze entire tracks, use the Filter function. See Filter Tracks.
• You can also combine Filter and Nest boxes to create complex selections. See Complex Data Selections.

How to Select Track Segments

1. Create a new data profile or open an existing one.
2. Locate the variables under Nesting or Nesting over Subjects in the Components pane that you want to use to select track segments, and click the corresponding button. A Nest box appears in the top-left corner of the Data Profiles screen and a new window opens on top.
3. Select the values that define the track segments you want to analyze, and click OK.
4. Drag the Nest box to the desired position between the Start and the Result box. See Insert a Box in a Data Selection Sequence.
5. Repeat steps 2 to 4 to add more Nest boxes and refine your selection. If you want to edit an existing Nest box, click the Settings button in that box.
6. Choose Analysis > Results > then one of the options available to obtain numerical and graphical results for the track segments selected.

Notes

• If you have tracked two or more subjects per arena, you have two main nesting options:
  • Nesting — choose this category if you want to analyze the track segments that correspond to the behavior of the subject of that track.
  • Nesting over Subjects — choose this category if you want to analyze the track segments that correspond to the behavior of subjects other than the subject of that track, or a combination of subjects. See Nesting over Subjects.