Like many mammals, rats are attracted to novelty. In order to recognize something in the environment as novel, there needs to be memory for what has been encountered before. The relative attention the animal will devote to the novel compared to the familiar in the environment can therefore be used as a proxy for available memory.The novel object recognition task makes use of this effect and is widely employed in memory research, where it is considered a good model for human declarative memory. With lab- and task-specific optimizations, the task produces robust, reliable results.

In our lab, the task typically consists of three phases – Habituation, Sampling, and Probe.

1. Habituation. Animals are repeatedly exposed to the testing environment. We use an open field, 600 mm X 600 mm X 600 mm. Typically, they explore the empty open field one time per day for four consecutive days.
2. Sampling. Objects are placed in the open field, and rats are returned to explore it. It depends on the experimental question how long and how often this is done. Typically, we place two identical copies of objects in the same positions into the open field during the Sampling trials, usually in opposing corners, with a distance to the wall enough for rats to run around them..
3. Probe. At least one novel object is introduced to the open field, everything else stays the same. Typically, we replace one of the two objects with a new one. If rats explore the novel object longer than the old one, this behaviour is interpreted as novelty recognition and that the animal has memory for the familiar object.

During Habituation, animals are repeatedly exposed to the square open field. This serves to familiarize them to this environment. Then, during Sampling, animals return to the open field, that now contains objects. In the most simple form,

Typically, animals are exposed to objects in a familiar open field during the Sampling phase, and at a later point, they are re-exposed to the open field during the Probe phase, in which some objects from the Sampling phase have been replaced