# Nesting over time

Aim

To pick out the samples in one time interval, from time tstart to time tend.

Procedure

1.In the Data Profile, under Nesting click the button next to Time.

note Choosing Time under Nesting over subjects leads to the same data selection.

2.In the Time window, enter the Interval start and Interval end.

▪Relative time is the time since the start of the track. Enter the relative time. In EthoVision XT 17.5 and later, you can specify any time within the trial, even after 24 hours.

▪Track start/Track end mark the start and end of each track, respectively. Therefore, they may mean different relative times between tracks.

3.Complete the procedure from step 4 in How to select track segments.

examples

▪To analyze the first 10 minutes of each track:

▪To analyze the from 10 minutes to the end of each track:

Notes

▪Time intervals are applied in each track independently (see also the notes below).

▪Default: Interval start 0:00:00.000 (h:mm:ss.fff), Interval end 0:00:30.000.

▪0:00:00.000 represents the time that tracking started for that arena. With multiple arenas, tracks may actually start at different times within the same trial (see below).

▪If you want to split the data in regular intervals (for example, a one-hour recording in six 10-minutes intervals), do not nest over time. Instead, in the Data profile choose Results per time bin .

▪tip If you want to select a track segment that lasts some time relative to an event (for example, select the 10 seconds after the presentation of a stimulus, or select up to when an object is explored for 1 minute), then choose Free interval instead. See Nesting over a Free interval.

▪Nesting over time when working with multiple arenas. if you apply Trial Control with Start and Stop conditions for each arena separately, actual data recording may start and stop at different times in each arena.

The example below shows the effect of Nesting over the first minute of the tracks, in an experiment with two arenas. Dots represents the samples on the timeline. Tracking started automatically as soon as the animal was detected in the arena. Because the mouse in Arena 1 was released (and therefore detected) earlier than in Arena 2, tracking started earlier in that arena. The tracks have equal duration set in the Trial Control Settings, for example 5 minutes. When nesting over time, we select the first minute of each track (from Track start to 0:01:00.000). As a result, the two track segments do not overlap completely on the time line.

▪Nesting over time when working with multiple subjects per arena. Within an arena, tracking starts at the same time for all subjects. Therefore, nesting over time results in the same interval being selected for all the subjects.

Note that tracking starts for all subjects even when one is not released yet in the arena. In that case the track for that subject starts with missing samples.