Behavioural tests: Training procedures

Now that we’ve covered the first category of behavioural tests, let’s move on to the second: training procedures.

In training procedures, subjects are taught an explicit rule to see whether they have the cognitive ability to support it.

In this case, subjects—or animals are required to learn a perceptual or cognitive rule.

Establishing a shaping procedure

At the beginning, the animals are usually confused and only choose randomly. However, if they have the cognitive skill under investigation, trial after trial, they are expected to successfully discriminate between the stimuli.

Choosing a learning criterion

When we try to teach a rule, it is fundamental to ensure that the rule we are looking at is the only one that permits the discrimination between two stimuli.

Rule Number 1: Select the blob with a smaller area.

Rule Number 2: Select the figure with angles.

Therefore, to teach an abstract rule, it is necessary to present different versions of the positive stimulus (the one associated with the reward) and negative stimulus (the one that isn’t associated with the reward).

The positive stimulus may vary in shape (although it will always be a triangle), orientation, and area, so that the animal cannot use what we call a pattern recognition, like a picture of the single stimulus. Instead it has to extract a rule from all these positive stimuli, such as ‘it’s the figure that always has three angles’.

Similarly, the negative stimuli could be different types of circles, but also other figures, especially with angles, so that the previous rule “select the figure that presents an angle” is no longer enough to find the stimulus associated with food.

_{Avoiding pattern recognition through the use of multiple stimulus pairs}

So as a general rule of thumb, use multiple stimulus pairs: Your first pair is always a triangle vs. something else. And then the second is always a different triangle vs. a different figure on the other side. The only way to solve this task and eat the reward is by learning the rule “select the triangle”.

Kinds of rewards

When you think about training studies, you always think about a food reward, and indeed this is the most common type of reward for mammals and birds.

But cold-blooded species are not similarly motivated to reach food often during the day therefore, this type of reward may be less effective compared to mammals and birds. In this case, a different type of reward is needed. If the species is highly social, for instance, the possibility to reach social companions is a powerful reward. You’ll find out more about this when we talk about guppies.

Wrapping it up

In summary, in training procedures, an animal is required to learn a rule. This generally requires the presentation of several dozens of stimuli in which there is a positive and negative stimulus. Most of these studies use food as a reward, but in some cases, a social reward has also been used.