Knowledge Base

The Trial Control Screen

To access the Trial Control screen, in the Experiment Explorer, click Trial Control Settings 1 in the Trial Control Settings folder, or from the Setup menu, select Trial Control Settings, then click Open and select Trial Control Settings 1. The Trial Control screen appears, showing the default Trial Control settings.

You can also access the Trial Control screen by creating a new Trial Control Settings, or opening one other than Trial Control Settings 1.

The Trial Control screen contains the following components:

• Components Pane: Lists the conditions on which you can base your actions and the operators which you can use to combine conditions.
• Trial Control Window: Shows the Trial Control Settings that are active. It contains a sequence of boxes connected by arrows.
• Maximum Trial Duration Pane: Allows you to define a maximum duration for all trials.

You can show or hide the Components pane and the Maximum Trial Duration pane by clicking the Show/Hide button on the components toolbar and selecting or deselecting the corresponding option in the menu.

The Components Pane

With the Components pane you choose the blocks that build up your trial control rules. Expand the list by clicking the More button.

Not all the components listed below may be available on your screen, depending on what EthoVision XT license you have on your computer.

Conditions

• Time
• Time Interval
• Trial Control Variable
• Dependent Variables: To define a condition based on a variable that describes the animal's behavior, for example velocity, presence in a zone, movement, etc.

  Note: You cannot define a condition based on behaviors scored manually, behaviors detected automatically with Behavior Recognition, Activity state, Acceleration state, or Free intervals.

• Hardware: To define a condition based on the state of a hardware device. If devices are not listed, you must first configure EthoVision XT so that it recognizes the devices.

Actions

• Trial Control Variable
• External Command
• Hardware

Structures

• Sub-Rule: To define a subroutine that can be called from a specific point of the Trial Control sequence.
• Operator: To combine two or more conditions in such a way that an action is taken when All, Any, or N of All conditions are met.
• Reference: To insert a call to a sub-rule within a sequence of instructions.

To Define a Sub-Rule, Condition, Action, or Operator

Do one of the following:

• Double-click its name.
• Click the button next to it.
• Drag the name from the Components pane to the middle of the screen.

A new Trial Control box appears in the top-left corner of the Trial Control window. Insert the new box in the sequence of boxes.

The Trial Control Window

The Trial Control window contains the sequences of instructions (rules) currently present in the Trial Control Settings. When you create a new Trial Control Settings profile, the Trial Control window contains the default Start-Stop trial rule, consisting of six boxes connected by arrows.

You can then define:

• Your own conditions that determine the start and stop of data acquisition.
• If your EthoVision license includes Advanced Trial Control:
  • Additional sub-rules — sequences of actions and conditions that work like subroutines in a program, which can be called from another point in the Trial Control sequence.
  • Control hardware devices, such as a food dispenser or a door.

Grid

The Trial Control boxes automatically snap to a grid. You can change this by clicking the Show/Hide button on the component toolbar and selecting or deselecting the two Grid options (Snap to Grid and Show Grid).

Zoom

The component toolbar of the Trial Control Settings shows three zoom icons:

• Zoom In: You can keep zooming in until all Trial Control boxes fit in the window.
• Zoom Out
• Zoom to Fit: Clicking this button fits all Trial Control boxes into the window.

The Trial Control window is dynamic, meaning it expands when you move Trial Control boxes to the right. You can navigate from left to right in the Trial Control window using the scroll bar at the bottom. Use the Zoom to Fit button in the component toolbar to make all Trial Control boxes visible.

Trial Control in Special Cases

• If you selected Activity Analysis in the Experiment Settings, the first condition box is removed from the default Start-Stop rule. To carry out tracking and activity analysis simultaneously and start tracking when your subject is detected in the arena for a specific time, insert a new In Zone condition box in the Start-Stop rule.
• If you selected Behavior Recognition in the Experiment Settings, the default Trial Control rule also contains a Time condition box (3 seconds), meaning that tracking starts 3 seconds after starting the trial.
• If you selected both Activity Analysis and Behavior Recognition in the Experiment Settings, the same Trial Control rule is used as for Behavior Recognition only.

To Export Trial Control Settings

You can export an image of the Trial Control Settings:

1. Click the Export Image button on the toolbar.
2. Select a location to save the image to, type in the File Name or accept the default, and select an image type from the Save as Type list.
3. Click Save.

The complete Trial Control window is exported, irrespective of the zoom factor.

Maximum Trial Duration Pane

Use the Maximum Trial Duration pane to define a maximum duration for the trial. This prevents EthoVision XT from waiting indefinitely for a condition to be met.

Source: EthoVision XT 18 - THC - Trial and Hardware Control, Noldus Information Technology