22.3 Stimulus Features

The first concept we’ll discuss related to the extension of verbal behavior is stimulus features. We talk about behavior being under the discriminative control of a stimulus. Most often we talk about a stimulus as being some object or event, such as a dog or an explosion. A very common stimulus in animal research is a light onset. But a light has many properties, such as intensity, color, duration, position, shape, etc. As Skinner pointed out in his remarks about tact extension, any feature of an occasion (object or event) appears to gain some control over a response that is reinforced at that time. However, it is generally the case that the person presenting the stimulus wants the organism to respond under the control of only one or a few of the features present at any given time.