Knowledge Base

Independent Variables Tab

The Independent Variables tab is a simplified version of the Trial List. It shows the user-defined independent variables and the Acquisition status for the acquired trials and the planned trials.

Row Colors

• Before acquisition, the current trial (about to be acquired) is highlighted in green. Acquisition status says Ready to start.
• During acquisition, the current trial is highlighted in red. Acquisition status says Acquiring.

Dependent Variables Tab

In the Dependent Variables tab you can view any dependent variable in real time during acquisition, for each subject and arena. By default, it shows the following variables: Velocity and Movement.

To view more variables during a trial, see Choose a Variable to View Real-Time.

Important: Adding variables may reduce performance and increase missing samples. Select only the variables and its properties you are interested in. For example, if you are interested in monitoring the Immobile state during a Porsolt swim test, add the Mobility state variable, then select Immobile and deselect the other two states under Calculate for state in the Mobility State properties window.

Manual Scoring Tab

See Score Behaviors Manually During Acquisition.

External Data

Introduction to External Data

Work with External Data

External Data Types

You can import external data, like for example heart rate, EEG, GSR or accelerometer data into EthoVision XT and synchronize these data with the tracks. EthoVision XT can import data in ASCII format with a constant sample rate or a time stamp column in the file.

Note: It is also possible to import European Data Format (EDF) files, or BioSemi Data Format (BDF) files, which is the 24 bit version of EDF, into EthoVision XT. Import of EDF+ or BDF+ files, which may contain annotations, is not supported.

Procedure

Working with external data in EthoVision XT involves some basic steps:

1. When possible, connect the EthoVision XT computer to one of the input channels of the external DAQ system. This allows you to synchronize EthoVision XT and the external data automatically. See Connect EthoVision XT to the DAQ System.
2. Enable DAQ co-acquisition in EthoVision XT.
3. Acquire the trials, while the DAQ system acquires its own data. See Acquire a Trial Live for the general procedure.
4. After data acquisition, import the external data file(s) and assign them to a Trial, Arena, or Subject. See Import a Complete External Data File at Once. Tracking data and external data are automatically synchronized in case you used DAQ co-acquisition. If not, you can use manual synchronization.
5. Visualize external data together with video and acquired tracks.

Notes

• The external data are saved on the computer dedicated to the DAQ device, not on the EthoVision XT computer.
• If you want to visualize tracks according to the values of a dependent variable, make sure that you specify that dependent variable in the active Analysis profile. To edit a profile, click it in the Experiment Explorer and make the necessary changes.

Connect EthoVision XT to the DAQ System

Aim

To ensure that EthoVision XT sends a synchronization signal to the DAQ system during data acquisition.

Prerequisites

You must have:

• A free USB port on your EthoVision XT computer.
• A USB-to-Serial (COM) converter.
• A sync cable from Noldus. This cable has connectors that depend on the DAQ system you have.

Optional: Connect the two computers through a local network for easy data transfer from the DAQ system to the EthoVision XT computer. See Import External Data: General Information.

Notes

• It is also possible to ensure synchronicity between EthoVision XT and the DSI Ponemah system without a sync signal. See Sync the Computer Clocks for EthoVision XT and DSI Ponemah.

Enable DAQ Co-Acquisition in EthoVision XT

Aim

To program EthoVision XT to send a synchronization signal to the external DAQ system.

Procedure

1. In EthoVision XT, open your experiment.
2. Choose Setup > Experiment Settings.
3. Under Video Source, choose Live tracking and select the Enable DAQ co-acquisition box. Click the Edit button.
4. Under Predefined Settings, select the item corresponding to your DAQ system, or create a new one (see below).

Notes

• When you have acquired data, the Experiment Settings are read-only (settings are grayed out).
• You can only co-acquire external data when you carry out Live Tracking.

To Create a New DAQ Hardware Settings Profile

1. In the DAQ Hardware Settings window, click the New button.
2. A new field appears at the bottom of the list of predefined profiles. Type a name for the new profile.
3. Under Output device, select one of the COM ports from the list. This COM port is used to connect the EthoVision XT computer to the DAQ system. Click the Check Status button to check the availability of the port. It may be that either all COM ports on your PC are occupied, or your PC does not have a COM port. In those cases, contact Noldus for a USB-to-COM converter.
4. Under Signal Type, select:
   • On-Off if the external signals are sampled at low rate (less than 10 Hz) and without interruption (thus no scheduled sampling).
   • Time Code (TCAP) in all other cases. Enter the Sample rate (in Hz) with which you sample data on your DAQ system. If you want to sample data at a rate higher than 2 KHz, set 2000 Hz. Depending on the Sample rate, the Minimal sampling time changes; this indicates the minimum time the data should be acquired on the DAQ system for synchronization to work properly.
5. Click OK.

To Delete a DAQ Hardware Settings Profile

In the DAQ Hardware Settings window, select a Profile and click Delete or press Delete.

To Change the Order of DAQ Hardware Settings Profiles

In the DAQ Hardware Settings window, select a Profile and click the Move Up / Move Down button or press ALT-arrow down / ALT-arrow up on your keyboard.

To Add a Description to a DAQ Hardware Settings Profile

In the DAQ Hardware Settings window, select a Profile, click in the Description box and type in text. Click on another Profile and click Yes to save the Description.