Working with dynamic stimuli in the AOI tool

Learn how to create a dynamic AOI in Pro Lab by watching the video above or by following the instructions below. You can also try it in Pro Studio by following the instructions in the next section.

Let's get started! Much of the detail about the use of the tool can be found in chapter 8 of the Pro Studio and Pro Lab User Manuals, Creating and Managing AOIs. Using the Wildlife.wmv 30-second movie that comes with Windows systems, we're going to identify the key steps in applying the Dynamic AOI Tool after you've recorded a few participants.

In Pro Lab: 

1. Go to the  AOI tab (AOI tool) in Pro Lab and select the stimulus on the "Media Selection" panel.
2. Using the playback controls (play/pause, frame forward/backward) locate the point on the media’s timeline where you want to begin including gaze data for analysis using dynamic AOIs. In this case, just a few frames in from the beginning of the video.
3. Draw an AOI around the target, here, the sole white horse among a herd of brown horses. Doing so will place a keyframe marker the same color as the AOI onto the timeline. Using the playback controls, step forward until the horse has moved such that it is now beyond the boundaries of the AOI as defined in the first keyframe. Make sure you switch from AOI-Draw to AOI-Select mode in the toolbar and then drag the AOI to encompass the horse in entirety again. If the object has changed in size or shape over the course of the tracking movement. Repeat until the last frame where Dynamic AOI-based data inclusion is desired. At this point, click on the “AOI Active” toggle in the toolbar and set to “Off”. This will insure that only data during the time interval of interest is aggregated. In our video example, the number of key frames that are generated are low because the motion path of the white horse is simple and brief. If the target motion were complex, there could be significantly more.
4. Analysis proceeds then as with static AOIs on the Metrics tab. Select the metrics, recordings, time of interest (media) and Areas of interest to analyze and click on "Export" to generate the export file.

Tip: While the Dynamic AOI tool can be used to gather gaze data during the visual tracking of moving stimuli, be careful with the judgments made from the resulting data. If the object motion is large scale, smooth, and fast, then most likely the following eye motions will smooth pursuit instead of saccadic in nature. In this case, while total looking time to the target would still be valid, fixational measures would probably not make much interpretive sense.

Tip: For many applications, the AOI size may not change as the target moves or translates across the frame. However, if you dynamically resize an AOI across target motion, remember to keep in mind the selectivity and sensitivity considerations on AOI sizing that are explained in article Digging Into Areas of Interest

In Pro Studio:

1. Go to the Areas of Interest tab in Pro Studio and select the stimulus under the “Movies” media category
2. Using the playback controls (play/pause, frame forward/backward) locate the point on the media’s timeline where you want to begin including gaze data for analysis using dynamic AOIs. In this case, just a few frames in from the beginning of the video.
3. Draw an AOI around the target, here, the sole white horse among a herd of brown horses. Doing so will place a keyframe marker the same color as the AOI onto the timeline. Using the playback controls, step forward until the horse has moved such that it is now beyond the boundaries of the AOI as defined in the first keyframe. Make sure you switch from AOI-drawing to AOI-editing mode in the toolbar and then drag the AOI to encompass the horse in entirety again. If the object has changed in size or shape over the course of the tracking movement. Repeat until the last frame where Dynamic AOI-based data inclusion is desired. At this point, click on the “Activation” toggle in the toolbar and set to “Off”. This will insure that only data during the time interval of interest is aggregated. In our video example, the number of key frames that are generated are low because the motion path of the white horse is simple and brief. If the target motion were complex, there could be significantly more.
4. Analysis proceeds then as with static AOIs on the Statistics tab. Select the media to analyze, the metrics and descriptive statistics of interest, and the participants or participant groups and click on "Update" to generate the data tables.

Tip: While the Dynamic AOI tool can be used to gather gaze data during the visual tracking of moving stimuli, be careful with the judgments made from the resulting data. If the object motion is large scale, smooth, and fast, then most likely the following eye motions will smooth pursuit instead of saccadic in nature. In this case, while total looking time to the target would still be valid, fixational measures would probably not make much interpretive sense.

Tip: For many applications, the AOI size may not change as the target moves or translates across the frame. However, if you dynamically resize an AOI across target motion, remember to keep in mind the selectivity and sensitivity considerations on AOI sizing that are explained in article Digging Into Areas of Interest

Conclusion

The Dynamic Areas of Interest tool is a powerful function provided in Pro Studio and Pro Lab for the analysis of dynamic stimuli such as movies, animations, and other types of video recordings (e.g. glasses). Using dynamic AOIs, you can bring the full power of eye tracking statistics and automated AOI analysis to your moving stimuli.