Knowledge Base

Data Analysis

Analysis Profiles

The template experiment contains four analysis profiles:

• Distance & Time – With the variables Distance Moved and Velocity, the mean velocity and the total distance moved and the group means with their standard errors are calculated. The total distance moved is a measure of the activity of the test animal.
• Movement – With this analysis profile the behavior of the animals is divided into moving and not moving. The frequency, duration and latency to either of these states and the group means with their standard errors are calculated. Like total distance moved, movement is a measure for activity.
• In Zones – With this analysis profile, the frequency the animal visited the zones defined in the arena settings and the group mean with its standard error are calculated. The data profile also contains the total time spent in the zones and the latency until the animal first enters either of the zones.
• Behaviors – With this analysis profile, the frequency, duration and the group means with their standard errors of the manually scored behaviors are calculated. In the template experiment, the behaviors rearing and grooming are predefined. Possibly, you added additional behaviors like defecating, or urinating. You can add these behaviors to the analysis profile and calculate for example their frequency and duration.

Analysis Per Zone

To calculate distance or speed in a specific zone:

1. Choose Analysis > Data Profile > New. Click on the Settings button on the Result box, select Results per zone and subsequently select the zones you want to analyze.
2. Next, choose Analysis > Analysis Profile > open the analysis profile and select the variable (distance, velocity etc.).
3. Choose Analysis > Results > Statistics and Charts.

To calculate time spent in a specific zone:

1. Choose Analysis > Analysis Profile > New. Choose In zone, select the zones you are interested in.
2. Choose Analysis > Results > Statistics and Charts.

Time Variation of Behavior

Define Results per time bin. In this way, the dependent variables are calculated over each time interval.

1. Choose Analysis > Data Profile > New.
2. Click the Settings button on the Result box, select Results per time bin and specify the time interval.
3. Choose Analysis > Results > Statistics and Charts.

Zone Crossings

In addition to the predefined analysis profiles you can create an analysis profile for zone crossings. This way you can calculate the number of crossings from the border zone to the center zone.

1. Click the Add button next to Zone transition.
2. Select the zone sequence.
3. Depending on which option you select (Allow intermediate zone visits or Only count direct transitions) you can get different results. For more information, see the Zone transition in the EthoVision XT Help.

Freezing Behavior

If you want to quantify freezing behavior, which is a measure of the fear the animals experience, create an analysis profile for Activity state. Activity is defined as the amount of pixels in the arena that change at any time. Click the Add button next to Activity state and define the number of states and their thresholds (for freezing, the important threshold is Inactive below). On the Statistics tab, choose the statistics. With this analysis profile the behavior of the animals is divided into the states you specified.

Next, use the Plot Integrated Data function to visualize the activity states. Adjust the settings in the Analysis profile until the state "Inactive" matches the freezing behavior of the animal in the video. The frequency, duration and latency to all those states is calculated in the next step (see Calculating Statistics).

For more information on Activity, see the EthoVision XT Help.

Stretch-Attend

Stretch-attend postures can be detected with the Body elongation state variable in the Analysis profile.

For more information, see Body elongation state in the EthoVision XT Help.

Rat or Mouse Behavior Recognition

To analyze the automatically detected behaviors, in the Analysis profile under Rat or Mouse Behavior Recognition choose the behaviors you are interested in.

Furthermore:

• If you want to analyze multiple behaviors as one, click Merged Behavior.
• If you want to view the probability (that is, a measure of detection uncertainty) associated with the behaviors detected, click Behavior probability and specify the behaviors you are interested in.

Comparing Groups

1. Prerequisite: You can define groups of tracks based on independent variables.
2. Choose Analysis > Data Profile > New.
3. Create a structure like that in the following picture. To create a new branch, click the button next to Result and connect the Start box with the new Result box.

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 treated with saline and red for drug-treated animals). 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 Heatmaps – You can make heatmaps of the location of the subject.
• 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.

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