Knowledge Base

Nesting Over a Trial Control State

Aim

To pick out the track segments corresponding to a Trial Control state. A Trial Control state is an interval defined by two events occurred during the trial (a condition met, a sub-rule started, an action taken etc.). To learn more about Trial Control states, see Trial Control state in the Analysis profile.

Example: Calculate the average velocity of the subject between the time that the light went on to the time that the pellet was given.

Procedure

1. In the Data Profile, under Nesting click the button next to Trial Control state.
2. In the Trial Control State window, select the Trial Control elements that define the start and the stop of the interval to analyze. For details about how you can define a Trial Control state, see Dependent Variables in Detail > Trial Control state.
3. Click OK. Proceed with step 4 in How to Select Track Segments.

Notes

• If the Trial Control state occurs more times in your trial, like those defined with events in a subrule, there will be multiple selection intervals in one trial. You have the following options:
  • Select Calculate result for interval if you want to restrict your selection to just one interval, for example the first one, or the third one. Next to For consecutive intervals, enter the number of the interval (1 for the first).
  • Leave Calculate result for interval not selected if you want to select all the resulting intervals. Analysis is based on all those intervals merged in one.
• The Actors tab in the Trial Control state window is of no use, because Trial Control states occur at the trial and arena level, independent of the subjects. You cannot assign a Trial Control state to a specific subject.

Nesting Over a Free Interval

With Nesting over a Free interval you can define the beginning and the end of a track segment, and analyze the dependent variables within that segment.

For example, define an interval that goes from the start of the track to when the subject has explored an object for a total of 30 seconds. Then, analyze the zones that the subject visited, or calculate the average speed in that interval.

• Nest over a Free Interval
• Examples of Nesting over a Free Interval

See also:

• Free interval in the Analysis profile

Nest Over a Free Interval

Aim

To pick out the track segments corresponding to a Free interval, i.e., the interval included between event (or time) A and event (or time) B. See Examples of Nesting over a Free Interval.

Example: Analyze the mobility of the subject in the five seconds immediately following administration of a stimulus. In this example, event A is the onset of the stimulus. Event B occurs 5 seconds after A.

Nesting vs. Nesting Over Subjects

If your trials contain multiple subjects in the same arena and you want to analyze data of one subject based on the behavior of another subject, click Free Interval under Nesting over Subjects. See Free interval based on multiple subjects.

Procedure

1. In the Data Profile, under Nesting click the button next to Free Interval.
2. In the Free Interval window, specify the criteria that define the start and stop of the interval. For details about how you can define a free interval, see Dependent Variables in Detail > Free interval.
3. Click OK. Insert the resulting Nest box in the appropriate position between the Start and the Result box. See How to Select Track Segments.

Notes

• Important: If a start criterion is not met in a track, EthoVision XT does not select any interval for that track.
• The following dependent variables are not available for the definition of start/stop criteria: Activity state, Acceleration state, and the behaviors of Rat and Mouse Behavior Recognition.
• Note the difference:
  • You define a Free Interval 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 in a certain track segment.
  • You define a Free Interval in the Analysis Profile when you want to analyze the interval itself. For example, you can calculate the duration of an interval. However, you won't get, for example, the average velocity in the resulting track segment. See Free interval in the Analysis profile.
• Multiple occurrences of the interval. If the interval defined in the Data profile results in multiple occurrences within a track, you can nest over a specific interval occurrence. Select Calculate results for interval and enter the number of the occurrence. For example, 10 to nest over the 10th occurrence of the interval. Other occurrences are not used in the analysis. If you do not select Calculate results for interval, analysis is done in all occurrences merged into one result.
• Nest over a Free interval based on external data. If you imported external (physiological) data, you can analyze the track segments that correspond to a free interval based on external data. For example, nest over a Free interval that goes from the track start to when Heart rate reaches 400 bpm. If you want to select the track segments between two values of external data, for example from Heart rate = 300 to Heart rate = 400, then choose Nest over external data (state) instead.