Knowledge Base

Background

This topic contains details about defining a Free interval. For the main procedure, see Free interval.

To Specify the Trial Control Event

In the Free Interval window, under Start criterion or Stop criterion, choose Trial Control and select the following:

1. In the Start at / Stop at field, enter the time of the start (or stop) of the interval relative to the Trial Control event specified in the next steps.

   Example: To start an interval 1 s before a Trial Control condition becomes true, next to Start at enter 0:00:01:000 before event.

   Example: To stop an interval 10 s after the Trial Control action "Drop pellet", next to Stop at enter 0:00:10:000 after event.

2. From the Occurrence list, select which occurrence should mark the start of the interval (1st to 9th).

   Select 1st if you want to define an interval from the first time that a trial control event occurs. Select 2nd, etc. when the trial control event occurs repeatedly, for example in sub-rules.

3. From the Element list, select the trial control category (condition, action, sub-rule, etc.).

4. From the Event list, select the event. The options differ depending on the Element chosen.

   • For actions, sub-rules: becomes active/inactive.
   • For conditions: becomes active/inactive, and becomes true/false.
   • For sub-rule references: becomes active/inactive, and makes sub-rule active/inactive.

Notes

• A Free interval can only start at the time that, or before (not after) a Trial Control event occurs. Similarly, a Free interval can only end at the time that, or after (not before) a Trial Control event occurs.

See Also

• For information on the meaning of active/inactive, false/true, see How the trial control instructions are executed.
• For information on sub-rules and analysis of trial control data, see the EthoVision XT 19 - Trial and Hardware Control - Reference Manual.

Nesting Over a Trial Control State

With Free intervals you can select the same track segments that you can define with Nesting over a Trial Control state in the Data profile. The main differences are that:

• With a Free interval, you can also specify the number of occurrences of an event in the Interval start criterion. For example, define an interval that starts when an action is carried out the 3rd time. With Trial Control state that is not possible. There, you can only specify the number of occurrences in the Interval stop criterion.
• With a Free interval, you can combine Trial Control events with other criteria (time, dependent variable values, hardware log values). For example, define an interval that goes from the time a light switches on, to 1 minute after that time.

To Specify the Hardware State or Value

In the Free Interval window, under Interval start or Interval stop, choose Hardware and select the following:

1. In the Start at / Stop at field, enter the time of the start (or stop) of the interval relative to the Hardware event specified in the next steps.

   Example: To start an interval 1 s before the PhenoTyper's white light switches on, next to Start at enter 0:00:01:000 before event.

   Example: To stop an interval 10 s after a pellet was dropped, next to Stop at enter 0:00:10:000 after event.

2. From the Select device type list, choose the type of device you want to use.

3. From the Select name list, select the name of the device of the chosen type. The names in this list have been assigned to that device type in the Arena - Hardware mapping window in the Arena Settings.

4. From the Select signal/command list, select the variable or the command you are interested in.

5. From the Signal value list, choose which value the signal should have to define the start/stop of the interval, using the operators available (<=, >= or false/true).

Notes

• The Cumulative value option is available for numerical variables like Number of pellet drops, Number of licks, Duration of licks, or counts (for example, Input 1 L->H count).

• When Cumulative value is selected, hardware events are summed up and EthoVision "remembers" that at any time. Keep this option selected if, for example, you want to start an interval when the Signal value is >= 10.

• When Cumulative value is not selected, each hardware event is a state that lasts one sample time (for example, 0.04 s if the sample rate is 25). At any time, EthoVision does not "know" how many events have occurred up to that time. De-select Cumulative value when you want to specify multiple intervals, for example for each time a pellet is dropped.

• The options under Interval start and Interval stop are based on the Hardware state dependent variable. For more information, see also Hardware state under Analysis of Trial Control data in the EthoVision XT 19 - Trial and Hardware Control - Reference Manual.

See Also

• The EthoVision XT 19 - Trial and Hardware Control - Reference Manual. To open this manual, on the Windows Apps screen choose Noldus > EthoVision XT 19 Other documentation.

Source: EthoVision XT 19 Help, Noldus Information Technology