The Rescorla-Wagner Model: what it is and how it explains learning
In 1972, Robert A. Rescorla and Allan R. Wagner proposed a very relevant theoretical model for the psychology of learning. It is the Rescorla-Wagner Model , based on classical conditioning and the concept of surprise.
Here we will know the characteristics of this model and what it intends to explain.
Rescorla-Wagner model: features
The Rescorla-Wagner model was presented in 1969 in a series of lectures on classical conditioning in Canada. It is the most influential theory of classical conditioning, and the one that has generated the most research.
The authors, initially gave it the name Variations in the effectiveness of reinforcement and non-reinforcement , but later it was recognized as the Rescorla-Wagner Model (1972).
The model is based on classical or Pavlovian conditioning, beyond associative learning of contingent stimuli. The aim of the Rescorla-Wagner Model is to predict and describe the changes (test by test) in the associative force that binds a conditioned stimulus (or more) to the unconditioned stimulus.
The central idea of the model is the competition that occurs between various stimuli to be associated with the unconditioned stimulus. In addition, it highlights other concepts that we will see below.
The associative force
In the model, conditioning is proposed as a variation in the associative force that relates conditioned stimuli to unconditioned ones. The essential parameters are their respective intensities or their “salience” (central concept of the model).
This associative force is an intervening or intermediary variable, which integrates stimuli and responses. It is inferred mathematically through the measurement of the conditioned response.
On the other hand, the associative force is limited (values from 0 to 100). Once an EI is no longer surprising because it is already predicted by an EC with 100% confidence (associative force of 100), there is no need to continue learning, even to predict it with another EC.
Unconditioned Stimulus Surprise
Depending on the model, conditioning or learning will occur when the unconditioned stimulus (EI) is unexpected (EI surprise) . That is, the animal learns about a CD when the CD is unexpected.
In this way, if the EI is surprising, the animal will look at the conditioned stimuli that precede it, that is, it will learn to be able to better predict in the future that the EI is approaching, from the ECs. According to Rescorla and Wagner, this learning is a tremendously useful capacity for survival in animals.
On the other hand, if EI is not unexpected (no surprise), it will not be possible to continue learning .
If we relate the surprise with the associative force already commented, we know that the more surprising an EI that appears after the EC, the less associative force that EC has with that EI (because if it surprises us, it is that we expected that the EI would not appear). In other words, the EI gives the associative force to the EC according to the surprise.
How does learning take place?
Thus, as we have seen, classical conditioning occurs as a result of quantitative variations in the associative force between conditioned (ECs) and unconditioned (EIs) stimuli .
Variations depend on a positive or negative discrepancy between the associative force that the organism has at a given moment and the true association that occurs in the environment between CIs and EIs.
These variations consist of changes that the greater they are, the more conditioning or learning they will produce.
Posterior model: Mackintosh’s theory
The first theory to emerge as a competition to Rescorla-Wagner’s model was Mackintosh’s theory of attention (1975). This theory does not assume that learning depends on the discrepancy of the associative force between a conditioned stimulus and a constant value of the unconditioned stimulus.
Instead, it states that the value of the conditioned stimulus is not constant for the organism but changes through experience.
Mackintosh’s theory states that pre-exposure to a stimulus makes it difficult to condition it later (the appearance of the conditioned response). That is, if animals are exposed to a CD before conditioning with the IE, they end up “interpreting” that this CD is irrelevant.
Mackintosh also suggested that animals try to get information from the environment that will allow them to predict the occurrence of biologically relevant events (BI).
- Pérez-Acosta, A. (2001). The Rescorla model: Wagner at twenty. Theory and foundations. Revista psicologíacientífica.com
- Pérez-Acosta, A, Rozo, J. and Baquero, H. (2003). Milestones of the molar perspective of classical conditioning. Psychology from the Caribbean, 12, 2-12.