Knowledge Base

2 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. To access the Trial Control screen, you can also create a new Trial Control Settings, or open one other than Trial Control Settings 1. The Components pane, listing the conditions on which you can base your actions and the operators which you can use to combine conditions. See the next page. The Trial Control window, showing the Trial Control Settings that are active. It contains a sequence of boxes connected by arrows. See page 19. The Maximum Trial Duration pane that allows you to define a maximum duration for all trials. See page 21. You can show/hide the Components pane and the Maximum Trial Duration pane by clicking the Show/Hide button on the components tool bar and selecting/deselecting the corresponding option in the menu. Figure 6 The Trial Control Settings screen. A - Components pane, B - Maximum Trial Duration pane, C - Trial Control window.

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 (see page 14).

Figure 7 The Components pane for Trial Control, with its main

groups Conditions, Actions and Structures. Under Conditions

and Actions, you see examples of hardware devices controlled

by EthoVision XT: a Pellet dispenser and a PhenoTyper Top Unit.

Conditions

Time. See page 67. Time interval. See page 69. Trial Control variable. See page 71. Dependent variables. To define a condition based on a variable that describe the animal's behavior, for example velocity, presence in a zone, movement etc. See page 72. note You cannot define a condition based on behaviors scored manually, behaviors detected automatically with Behavior Recognition, Activity state, Acceleration state and Free intervals. Hardware. To define a condition based on the state of a hardware device. See page 79. If devices are not listed, you must first configure EthoVision XT in such a way it recognizes the devices. See page 104.

Actions

Trial Control variable. See page 28. External command. See page 31. Hardware. See page 117.

Structures

Sub-rule. To define a subroutine that can be called from a specific point of the Trial Control sequence. See page 55. 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. See page 34. Reference. To insert a call to a sub-rule within a sequence of instructions. See page 57.

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. For the complete procedure for programming Trial Control, see page 23.

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 (see page 47). You can then define: Your own conditions that determine the start and stop of data acquisition. If your EthoVision license includes Advanced Trial Control (see page 14): Additional sub-rules, that is, sequences of actions and conditions that work like subroutines in a program. They can be called from another point in the Trial Control sequence. Control hardware devices, like a food dispenser or a door. For details on how to move, copy, connect and delete Trial Control boxes, see the EthoVision XT Help.

Grid

The trial control boxes automatically snap to a grid. You can change this by clicking the Show/Hide button on the component tool bar and selecting/deselecting the two Grid options (Snap to Grid and Show Grid).

Zoom

The component tool bar 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': this means that it expands when you move trial control boxes to the right. In this case, you can navigate 'from left to right' in the Trial Control Figure 8 The Trial Control window. By default, it contains the Start-Stop trial rule. window by using the scroll bar at the bottom. Use the Zoom to fit button in the component tool bar 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. For more information on Activity analysis, see the EthoVision XT Help. If you selected Behavior recognition in the Experiment Settings, the default Trial control rule also contains a Time condition box (3 seconds). This means 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 only Behavior recognition. For more information, see Behavior recognition in the EthoVision XT Help.

To export Trial Control Settings

You can export an image of the Trial Control Settings: 1. Click the Export image button on the tool bar 2. Select a location to save the image to, type in the File name or accept the default one 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

Aim

To define a maximum duration of the trial. This prevents EthoVision XT from waiting indefinitely that the condition to stop the trial (see page 47) is met. example In a novel object test, in the Start-Stop Trial rule you have defined a condition 'stop the track when the mouse enters the zone with the familiar object'. it may happen that the mouse completely ignores the familiar object and only pays attention to the novel object. To prevent that EthoVision never stops tracking, set a maximum trial duration.

To access this option

In the Trial Control Settings screen, locate the Maximum Trial Duration pane, right below the Components pane. If you do not see it, click the Show/Hide button on the tool bar and select Maximum trial duration.

Notes

Instead of using a Maximum trial duration, you can also define a condition based on time and place it immediately before the Stop track box (see page 47). However, there are two important differences: If you use the maximum trial duration, the program counts the time from the start of the trial (this is indicated by the Start-Stop trial box). Instead, a condition placed immediately before the Stop track box considers the time from the start of data recording (this is indicated by the Start track box). The two starting points may not be the same if you have a condition between Start-Stop trial and Start track that makes data recording start some time later than the trial. With a multi-arena setup, a maximum trial duration stops the trial (and thus data recording) in all the arenas simultaneously, even when data recording had started at different times. Instead, a time condition placed between the Start track and the Stop track box stops data recording in one arena when the condition is met in that arena. This means that you can have data recording stop at different times in different arenas. example You set to start data recording when the animal is detected for the first time in its arena. For this purpose, you make an In zone -based condition. Next, you define a 5- minutes Time condition, and place it immediately before the Stop track box. It the animals are detected for the first time at different times in different arenas, data recording stops at different times too, because of the 5-minutes interval set for all arenas. The trial ends when the recording stops in the last arena. The Maximum trial duration is not applied when you record video with the option Save video only, track later. You must stop video recording manually. When you track from the resulting video file, the Maximum trial duration is applied.

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Source: EthoVision XT 17 - Trial and Hardware Control Reference Manual