Knowledge Base

Data Analysis

Data Preparation

Data Editing

Choose Acquisition > Edit Tracks. You can fix tracking errors and swap back nose-points and tail-points that have been swapped in tracking. Normally you will not need to edit your data.

Smoothing Data

Choose Acquisition > Track Smoothing Profile and open MDM Filter 0.2 cm. In this profile, the Minimal Distance Moved filter is used with a value of 2 mm and option Direct.

Review Video and Behaviors

If you have scored behaviors manually, you can review the video and if necessary edit the data. Choose Acquisition > Score behaviors manually. For details, see Acquire Data > Score behaviors manually in the EthoVision XT Help.

Analysis Profiles

The template experiment contains four analysis profiles:

• Distance and Velocity. For quantifying activity and exploration. Combine this with a Data profile that specifies Results per zone.
• In Chambers. To calculate the time spent in each of the three chambers.
• Behaviors. To analyze behaviors scored manually (rearing and sniffing) or the time that the nose point was detected in the area around each cage (sniffing zone).
• On Cage. To calculate how often and how long the center point of the subject was found in the zone "cage" (left and right). This correlates with the time the mouse spent on top of the cages.

Add other analysis profiles according to your research questions. Click one of the buttons in the Dependent Variables pane and open the Trial Statistics tab to select which statistic to calculate.

Example

The researcher wants to know the time from the moment the animal is entirely in the right compartment to the first moment the animal's nose-point is close to the cage in the same compartment.

To calculate this time, in the Analysis profile choose Free Interval. Select an interval that goes from the time when the Current value of In zone, for zone Cage right, and for all body points, is "true" (Start criterion), to when the Current value of In zone for the zone Interest zone right, and for the nose point, is true (Stop criterion).

In the Statistics tab, select Cumulative duration.

For more information, see the EthoVision XT Help.

Visualizing Data

Choose Analysis > Results > ...

• Plot Tracks. You can view your tracks on a still image of the background. Tracks can be shown in different colors according to the values of independent variables (for example, blue for animals in Phase 2 and red for animals in Phase 3). Sample points can be shown in different colors according to the values of dependent variables, for example red when the animal was moving fast.
• Plot Integrated Data. You can look at a track with the video file in the background. When you plot integrated data you can also view Time Event plots of your independent variables. Just like with plotting tracks, you can show tracks or sample points in different colors.
• Plot Heatmaps. Make heatmaps of the location of your animals during the different trials. In the example below: Left heatmap: Cages empty. Right: mouse restrained in the Left cage (right cage empty).

Source: EthoVision XT 18 - Application Manual, Noldus Information Technology