An Interest Period is a specific time window that you define within a trial. Once an Interest Period is active, Data Viewer will filter your session, showing and reporting only the samples and events that occurred within that window.
How to Create an Interest Period
Click the dropdown menu at the top of the main window (it usually says "Full Trial Period") and select Edit....
In the Interest Period Manager, click the "New Interest Period" icon.
Define the start and end of your period. The most common method is to use messages sent from your stimulus presentation software (e.g., a message for stimulus onset and another for stimulus offset). You can also use fixed durations or other events like TTL inputs.
Managing Data Around IP Boundaries (Preferences)
You can control how Data Viewer handles events and Interest Areas that occur just outside or cross the boundaries of your Interest Period. You can find these settings in the Inspector > Preferences > Data Filters tab.
How to Create an Interest Period
Click the dropdown menu at the top of the main window (it usually says "Full Trial Period") and select Edit....
In the Interest Period Manager, click the "New Interest Period" icon.
Define the start and end of your period. The most common method is to use messages sent from your stimulus presentation software (e.g., a message for stimulus onset and another for stimulus offset). You can also use fixed durations or other events like TTL inputs.
Managing Data Around IP Boundaries (Preferences)
You can control how Data Viewer handles events and Interest Areas that occur just outside or cross the boundaries of your Interest Period. You can find these settings in the Inspector > Preferences > Data Filters tab.
- Show Interest Areas Pre/Post Interest Period: When checked, this displays Interest Areas that appeared on screen before or after the current Interest Period. Uncheck this to see only IAs from within the period.
- Hide Spanned Events: Hides any event (fixation, saccade, or blink) that crosses the start or end boundary of the Interest Period. These events will be completely excluded from all views and reports.
- Trim Spanned Fixation Duration: For fixations that cross a boundary, this option trims the duration, including only the portion of the fixation that falls inside the Interest Period in all calculations.