Knowledge Base

Problem

Users running the Hole Board test want to detect and quantify head dips (when the animal's nose or head enters a hole) using EthoVision XT's 3-point or nose-point tracking. They find it difficult to reliably detect nose-point contact with holes due to sensitivity limitations, and want to know if EthoVision can report the precise time the nose point is in a specific zone.

Details

EthoVision XT can track a nose point as part of 3-point tracking and detect when it enters a defined zone (representing a hole). However, there is no direct time-stamped report of exactly when the nose point is in a zone beyond what is captured by standard 'In Zone' parameters. The resolution of detection is frame-by-frame, so very brief contacts may be missed or over-counted depending on frame rate. A Data Profile can be used to filter analysis to only the periods when the nose point is inside the hole zone, but this still reports aggregate zone metrics rather than a precise event timeline. Relevant for Hole Board assays across EthoVision XT versions with 3-point tracking.

Solution

1. Ensure 3-point tracking is enabled and the nose point is correctly tracked for your trials (set up in the Experiment Settings under Detection Settings > 3-Point Tracking).
2. Define each hole on the Hole Board as a separate zone in your arena setup (small circular zones centered on each hole opening).
3. In the Analysis Profile, add the 'In Zone' parameter for the nose point for each hole zone. This will capture entries, exits, and time spent in each hole zone by the nose point.
4. To analyze only the periods when the nose point is in a zone, create a Data Profile with a filter that limits analysis to those time segments: go to Analysis > Data Profiles and add a filter condition restricting to frames where the nose point is 'In Zone' for the relevant hole.
5. Note that this approach reports aggregate statistics (total time, number of entries) for the nose point in each zone, not a precise per-event timestamp log. For finer event-level analysis, consider supplementing with Manual Scoring to mark discrete head dip events.
6. If head dips are brief and frequently missed, increase your camera frame rate to improve temporal resolution, or lower the zone boundary sensitivity by slightly enlarging the hole zones.
7. Export nose-point zone data to Excel for further per-hole analysis.