In psychology, a neutral stimulus (NS) is a stimulus that initially does not elicit a particular response from an organism. The concept of a neutral stimulus was introduced by Ivan Pavlov in his classic experiments on classical conditioning.
In classical conditioning, a neutral stimulus is repeatedly paired with an unconditioned stimulus (UCS) that naturally elicits a particular response (unconditioned response or UCR). Over time, the neutral stimulus becomes associated with the UCS, and eventually comes to elicit the same response on its own. At this point, the neutral stimulus has become a conditioned stimulus (CS).
Here are some examples of neutral stimuli:
In Pavlov's classic experiment, a bell was initially a neutral stimulus because it did not elicit a salivary response in dogs. However, when the bell was repeatedly paired with the presentation of food (which naturally elicited salivation), the bell eventually became a conditioned stimulus that elicited salivation on its own.
In a classroom, the sound of a bell or chime may be a neutral stimulus that initially does not elicit any particular response from students. However, if the sound is consistently paired with the beginning or end of class, the sound may eventually come to elicit a conditioned response such as students getting up to leave the classroom.
A particular scent may be a neutral stimulus if it does not initially elicit any particular response in an individual. However, if the scent is repeatedly paired with a positive or negative experience, the scent may eventually become a conditioned stimulus that elicits positive or negative emotional responses.
Neutral stimuli play an important role in classical conditioning, as they are the starting point for creating new associations between stimuli and responses. Understanding the role of neutral stimuli can help psychologists better understand how we learn and respond to the world around us.