Knowledge Base

Problem

Researchers measuring freezing during a fear conditioning paradigm want to extract activity state values (freezing/not freezing) separately for each tone presentation interval rather than only as an overall trial summary.

Details

EthoVision XT computes activity state (used as a proxy for freezing) across the whole trial by default. Users running fear conditioning with discrete tone presentations need per-tone freezing percentages or durations. Applies to EthoVision XT across versions using the Activity Analysis module.

Solution

1. In your Data Profile, open the Result box settings for the activity state or freezing parameter.
2. Select 'Results per time bin' and set the bin length to exactly match the duration of each tone presentation interval (e.g., 30 seconds if each tone lasts 30 seconds).
3. Ensure that your trial start time and bin boundaries align with tone onset times; if tones are delivered at irregular intervals, consider using Trial Control events or external event markers to define intervals rather than fixed time bins.
4. If tone timing is controlled via TTL or Trial Control rules, use the logged event times to verify bin alignment.
5. Export the binned results; each bin will correspond to one tone period, providing freezing duration or percentage per tone.
6. For more complex segmentation (e.g., pre-tone, during-tone, post-tone), use nested free intervals within the Data Profile to define custom analysis windows that match your experimental design.