Knowledge Base

Important Things to Know About Data Acquisition

Four Methods to Acquire Data

Choose the method that best suits your setup and experimental protocol:

• Acquire data live. The animals are tracked as they move in your experimental setup. The disadvantage of this method is that you do not have a video backup, so if you need to repeat data acquisition you have to repeat the test itself. See Acquire a trial live or Acquire a series of trials - live.
• Acquire data live and save video simultaneously. Like above, in addition EthoVision XT records video to a digital video file. You can use the video to re-do tracking if needed. See Acquire a trial live + save video or Acquire a series of trials live + save video.
• Record video with EthoVision XT, then acquire data. This is a two-step method. First, record video to a digital video file as the animals move in your experimental setup. Afterwards, open the video file and acquire the data. This way you are free to track data later. See Record video, then acquire a trial, or Record a series of videos, then acquire a series of trials.
• Acquire data from video files recorded with other programs. Use an external program, like MediaRecorder, to record video to a file while the animals move in the experimental setup. Later on, open the video file and acquire the data. See Acquire a trial from a video file recorded with other programs, or Acquire a series of trials from video recorded with other programs. See also Video file formats.

Advantages of Using Video Files

• You have a video backup. A video file is very handy since it allows you to acquire data for a trial once again, if needed. For example, if you realize that the detection settings were not optimal when you acquired the data. See Redo a trial.
• You make sure that tracking is reliable. When you track from a video file, let EthoVision XT take as much time as it needs to analyze each sample, independent of the actual frame rate. For example, if the detection method used requires a lot of time per sample, acquisition may be slower than real time, but you ensure that no sample is missed. See DDS (Detection determines speed).

Settings Used for Data Acquisition

You can view which settings were used for a particular trial. In the Experiment Explorer, click Trial List. Click the Show/Hide button on the toolbar and in the Show Variables window, select Arena Settings, Detection Settings and Trial Control Settings.

In the Experiment Explorer, settings profiles are marked with a lock icon, meaning that they cannot be edited. To edit a settings profile, make a copy.

To View Your Trials

Choose Setup > Trial List. Click the Show/Hide button on the toolbar. In the Show Variables window, select Acquisition status. For an explanation of Acquisition status, see System variables.

Correct Tracking Errors

Good detection settings do not generally result in tracking errors. Before editing tracks, make sure that the lighting conditions and the detection settings are optimized. See Edit the Tracks.

Acquire One Trial

Learn About

• Before you start acquisition

What Do You Want to Do?

• Acquire a trial live
• Acquire a trial live + save video
• Record video, then acquire a trial
• Acquire a trial from a video file recorded with other programs

See Also

• Acquire a series of trials (Batch acquisition)

Before You Start Acquisition

Screen Saver and Power Options

Turn off the screen saver and make sure that the power save options of your computer are turned off.

Video Cameras and Video Files

Make sure that the video cameras are connected to your PC's encoder board (for analog cameras) or USB/Ethernet ports (for digital cameras). See Camera Installation.

Use the Correct Settings

Make sure that the Arena Settings, Trial Control Settings and Detection Settings you want to apply are selected in the Acquisition Settings window.

Enter the Independent Variables for the Next Trial

In the Analysis Results and Scoring pane, click the Independent Variables tab and enter or select the values of the independent variables in the row highlighted in green. You can enter independent variable values at any time in the Trial List. See Independent Variables tab.

When Co-Acquiring External (Physiological) Data

If you want to acquire external data during the trial (only live, not from video files), make sure that the external data recording device is switched on and connected to the EthoVision XT computer. In EthoVision XT, in the Experiment Settings under Video Source select Enable DAQ co-acquisition. See also External Data.

NOTE: You must have the External Data Module in order to use this functionality.

Auto-Start Data Analysis

If you want to start analysis immediately after finishing the trial (or series of trials), in the Acquisition Settings window select Auto-start data analysis.

To Speed Up Analysis

• Hide the Analysis Results and Scoring pane. To do this, click the Show/Hide button and then deselect Analysis Results and Scoring.
• For tracking offline: Select DDS in the Playback Control window. This way EthoVision XT plays the video faster than 1x if subject detection requires little processor time.