Knowledge Base

Definitions

See also the reference in Notes.

Digging
Rooting with the muzzle or digging with the front paws in the bedding material (for Mouse Behavior Recognition only).

Drinking
The subject licks at the spout of the water bottle.

Eating
The subject eats at the feeder or from the floor, or is eating while holding food in front paws.

Grooming
The subject grooms snout, head, fur or genitals. Includes scratching and licking of paws during a grooming session.

Hopping
The subject moves forward with both hind limbs at the same time. Head goes first, followed by the rear. Unlike Jumping, Hopping is scored as a point event with no duration, and does not interrupt behavior states (for Mouse Behavior Recognition only).

Jumping
The subject moves quickly forward with both hind limbs at the same time. Jumping interrupts other states like Walking (for Rat Behavior Recognition only).

Rearing Unsupported
The subject stands in an upright posture, with front paws not in contact with any object. Includes the rise and descend.

Rearing Supported
The subject stands in an upright posture, leaning with front paws against the cage-wall. Includes the rise and descend.

Resting
The subject rests with hardly any moving, either sits or is lying down. Includes sleeping. Apparently no interest in the environment.

Sniffing
The subject makes slight movements of the head, possibly with slight, discontinuous body displacement. Includes sniffing the air, the wall, the floor and other objects.

Twitching
The subject makes sudden and short movements of the body or head. Includes body shake and head shake. Twitching is scored as a point event with no duration, and does not interrupt behavior states (for Rat Behavior Recognition only). Twitching is defined as a point event, that is, an event marking a point in the time line, but with no duration.

Walking
The subject moves to another place, and hind legs move as well. Note the difference between Walking and Movement: Both dependent variables Walking and Movement are based on displacement of the subject's body point in the 2D space. However, Walking is based on many more video frames than Movement, and therefore Walking is a more accurate measure of walking behavior.

How to Specify a Behavior for Behavior Recognition

1. Click the Add button next to the behavior you want to analyze.
2. Under Behavior decision method, select:
   • Default: Statistics will be calculated by using all samples scored as that behavior (no filtering based on the behavior's probability).
   • Probability greater than: Statistics will be calculated by using only the samples for which the probability of that behavior is higher than a specific value. Select this value from the list (0–99%).
3. Under Behavior duration threshold, next to Exclude instances shorter than, enter how long the current state must last before it changes from the previous state (in seconds). If the bout length passes this threshold, the previous samples in the bout are included in the new state. If the bout length does not pass the threshold, the previous state ends, but no new state is defined.
4. Under Calculate statistics for, select which state you would like to calculate statistics for.
5. Complete the procedure to add the variable. See Calculate Statistics: Procedure.

Accuracy

According to our tests, the average recall rate, that is, the proportion of ground truth manually-scored behaviors that are correctly recognized, is around 70%. For more information, see the paper mentioned below.

• Drinking can be confused with Sniffing especially when the Drinking Spout Points are not defined.
• Make sure to draw the Feeder Zones in the Arena Settings to maximize the detection accuracy of Eating.
• To maximize accuracy of detection of Rearing supported and reduce false positives, carefully draw the Wall zone in the Arena Settings.

Source: EthoVision XT 19 Help, Noldus Information Technology