Knowledge Base

Problem

A user needs to extract precise time points (at the second or millisecond level) for behavioral events (e.g., zone entries, social contacts) from EthoVision for synchronization with fiber photometry or calcium imaging data.

Details

EthoVision's standard raw data export provides sample-by-sample data, which can be used to identify in-zone status changes at the resolution of the sampling rate (typically per frame). For second-level precision, changes in the in-zone count column in the raw data export indicate entry/exit events. For millisecond-level precision, custom JavaScript code within EthoVision's analysis is required. This is relevant for users integrating with systems such as Neurophotometrics, Inscopix, or similar fiber photometry platforms. Affected versions: EthoVision XT (multiple versions).

Solution

1. For second-level event timing: export raw data from EthoVision (Analysis > Export > Raw Data). In the exported file, monitor the 'In Zone' count column for the relevant zone — a change in value (from 0 to 1 or vice versa) indicates a zone entry or exit event. The timestamp in the same row gives the event time at the resolution of the sample rate.
2. For millisecond-level precision: custom JavaScript code is needed within EthoVision's analysis to extract and report sub-sample timestamps. Contact Noldus support for guidance on implementing this.
3. For grooming or other behaviors: enable behavior recognition during acquisition so that behavioral state timestamps are recorded at acquisition resolution.
4. To synchronize with external hardware (e.g., Neurophotometrics fiber photometry): use TTL output via the USB I/O Box triggered by in-zone or behavioral state conditions in Trial Control — this provides hardware-level synchronization. See the article on configuring TTL output via USB I/O Box for details.
5. Ensure your EthoVision license includes the Trial & Hardware Control module if TTL synchronization is needed.