Animal Operant Learning

Animal Operant Learning

Animal Operant Learning

Introduction

Anticipating the future has a decided evolutionary advantage and many evolutionarily conserved mechanisms have been found by which humans and animals learn to predict future events. The marine snail Aplysia has been at the forefront of research into the cellular and molecular mechanisms of classical conditioning. Recently, it has also gained a reputation as a valuable model system for operant reward learning. Aplysia feeding behavior can be operantly conditioned in the intact animal as well as in reduced preparations of the nervous system. The reward signal relies on dopamine transmission and acts on known intracellular cascades to bring about operant memory in an identified neuron.

Discussion

As toddlers we already know how to attract our parents' attention by pretending to be crying. Learning to anticipate the consequences of our actions is central to shaping our personalities, beginning with processing social feedback down to the acquisition of motor skills such as a craft or handiwork. In our daily lives, much of this fundamental type of predictive learning takes place unnoticed, the brain subconsciously processing the constant stream of stimuli, assessing the importance of each one and cross-correlating them with our behavior. Some of the stimuli we encounter may have their own consequences, more or less independently of our behavior: the smell of fresh coffee brewing in the morning, the sound of a dentist's drill in the waiting room or dark clouds before a rainstorm are all signals of what's to come.

Obviously, we could not function without the capacity to learn the causes for future events. How does the brain accomplish this? How is the constant stream of relevant and irrelevant stimuli sorted and processed? In order to begin understanding the neurobiological processes that perform these tasks, the complexity of the environment has to be reduced to controlled, experimental circumstances. Ideally, the experiment would only contain two factors: a predictor and its consequence. Historically, such studies of predictive learning have been divided into two categories: one where the predictor is a behavior (operant or instrumental conditioning) and one where it is a stimulus (classical or Pavlovian conditioning). In both cases, the predictor is repeatedly followed by its consequence and the subject learns that relationship.

Operant Conditioning

Operant Conditioning shares many of the same features as Classical Conditioning, but is based on voluntary, non-reflex actions. In Operant conditioning an animal operates in its own environment and the consequences determine whether or not the action will be repeated. Behaviour can be changed by trial and error if it has been learned.

Conditioning can be found everywhere in the world, from school, to work and in your own home. It is a form of learning whereby those being conditioned are taught to either do something, or not do something, depending on the consequence of their actions. The learning involved is described as being voluntary, contrary to classical conditioning which is an involuntary learned behaviour, for example becoming ill at the sight of a hospital due to previous experience of being ill ...