This form of behavior modification involves the association of one event, as when the repeated presentation of a stimulus leads to an alteration of the frequency or speed of a response. Non-associative learning is considered to be the most basic of the learning processes and forms the building blocks of higher order types of learning in protostomes. The organism does not learn to do anything new or better; rather, the innate response to a situation or to a particular stimulus is modified. Many basic demonstrations of non-associative learning are available in the scientific literature, but there is little sustained work on the many parameters that influence such learning (i.e., time between stimulus presentations, intensity of stimulation, number of training trials).
There are basically two types of non-associative learning: habituation and sensitization. Habituation refers to the reduction in responding to a stimulus as it is repeated. For a decline in responsiveness to be considered a case of non-associative learning, it must be determined that any decline related to sensory and motor fatigue does not exert an influence. Studies of habituation show that it has several characteristics, including the following:
• The more rapid the rate of stimulation is, the faster the habituation is.
• The weaker the stimulus is, the faster the habitua-tion is.
• Habituation to one stimulus will produce habitua-tion to similar stimuli.
• Withholding the stimulus for a long period of time will lead to the recovery of the response.
Sensitization refers to the augmentation of a response to a stimulus. In essence, it is the opposite of habituation, and refers to an increase in the frequency or probability of a response. Studies of sensitization show that it has several characteristics, including the following:
• The stronger the stimulus is, the greater the probability that sensitization will be produced.
• Sensitization to one stimulus will produce sensitiza-tion to similar stimuli.
• Repeated presentations of the sensitizing stimulus tend to diminish its effect.
Was this article helpful?