Non-associative learning

Non-associative learning refers to learning that involves exposure to a single stimulus or event and how that particular stimulus increases or decreases a response.

Therefore, it does not include learning about a relationship between two stimuli or events (this is known as associative learning and you may be more familiar with these types of learning as they involve classical and operant conditioning principles).

The two primary types of non-associative learning are habituation and sensitisation.

Habituation occurs when you become less sensitive or responsive to a stimulus due to repeated exposure or stimulation. This is regarded as the simplest form of learning and it is important to distinguish habituation from declines in sensitivity or responsiveness due to fatigue or sensory adaptation.

For example, imagine that you’ve recently moved into a different house, apartment or living arrangement. While in bed on the first night, you’re able to hear traffic sounds from outside, wind blowing through the trees, and more, all with a heightened sense of attention. After a couple of days your sensitivity to this noise reduces and you become less agitated towards it. In other words, you become ‘habituated’ to the distracting stimuli.

In reality, habituation can last from minutes to hours depending on the type of stimulus and the strength of the repeated exposure. For instance, an individual may be more prone to habituation if repeatedly presented stimuli of ‘weak’ to ‘moderate’ intensity.

Following habituation, a phenomenon known as ‘spontaneous recovery’ may occur when the reduced response is restored to its initial state due to increasing time or when presented with another noxious stimulus.

Sensitisation occurs when you become more responsive to stimuli in the environment. This is essentially the opposite of habituation and has been referred to as ‘dishabituation’. For example, you could be undertaking an activity like studying in the library or focused on a task in the workplace. You hear the sound of someone chewing their food loudly and it evokes a strong reaction within you. Over time, the sound of the chewing may appear to grow louder and louder and your irritation towards it is also amplified.

Unlike habituation, sensitisation is likely to occur when organisms are repeatedly exposed to stimulation of moderate to strong intensity.