Learning is the process of acquiring new understanding, knowledge, behaviors, skills, values, attitudes, and preferences. The ability to learn is possessed by humans, animals, and some machines; there is also evidence for some kind of learning in certain plants. Some learning is immediate, induced by a single event, but much skill and knowledge accumulate from repeated experiences. The changes induced by learning often last a lifetime, and it is hard to distinguish learned material that seems to be "lost" from that which cannot be retrieved.
Classical conditioning is a behavioral procedure in which a biologically potent physiological stimulus is paired with a neutral stimulus. The term classical conditioning also refers to the subject animal's learning from the pairing of a physiologic stimulus with a neutral stimulus, which elicits the required response from the neutral stimulus rather than the physiological stimulus.
Eyeblink conditioning (EBC) is a form of classical conditioning that has been used extensively to study neural structures and mechanisms that underlie learning and memory. The procedure is relatively simple and usually consists of pairing an auditory or visual stimulus with an eyeblink-eliciting unconditioned stimulus (US). Naïve organisms initially produce a reflexive, unconditioned response (UR) that follows US onset. After many CS-US pairings, an association is formed such that a learned blink, or conditioned response (CR), occurs and precedes US onset. The magnitude of learning is generally gauged by the percentage of all paired CS-US trials that result in a CR. Under optimal conditions, well-trained animals produce a high percentage of CRs. The conditions necessary for, and the physiological mechanisms that govern, eyeblink CR learning have been studied across many mammalian species, including mice, rats, guinea pigs, rabbits, ferrets, cats, and humans. Historically, rabbits have been the most popular research subjects.
The mushroom bodies or corpora pedunculata are a pair of structures in the brain of insects, other arthropods, and some annelids. They are known to play a role in olfactory learning and memory. In most insects, the mushroom bodies and the lateral horn are the two higher brain regions that receive olfactory information from the antennal lobe via projection neurons. They were first identified and described by French biologist Félix Dujardin in 1850.
The Rescorla–Wagner model ("R-W") is a model of classical conditioning, in which learning is conceptualized in terms of associations between conditioned (CS) and unconditioned (US) stimuli. A strong CS-US association means that the CS signals predict the US. One might say that before conditioning, the subject is surprised by the US, but after conditioning, the subject is no longer surprised, because the CS predicts the coming of the US. The model casts the conditioning processes into discrete trials, during which stimuli may be either present or absent. The strength of prediction of the US on a trial can be represented as the summed associative strengths of all CSs present during the trial. This feature of the model represented a major advance over previous models, and it allowed a straightforward explanation of important experimental phenomena, most notably the blocking effect. Failures of the model have led to modifications, alternative models, and many additional findings. The model has had some impact on neural science in recent years, as studies have suggested that the phasic activity of dopamine neurons in mesostriatal DA projections in the midbrain encodes for the type of prediction error detailed in the model.
Extinction is a behavioral phenomenon observed in both operantly conditioned and classically conditioned behavior, which manifests itself by fading of non-reinforced conditioned response over time. When operant behavior that has been previously reinforced no longer produces reinforcing consequences the behavior gradually stops occurring. In classical conditioning, when a conditioned stimulus is presented alone, so that it no longer predicts the coming of the unconditioned stimulus, conditioned responding gradually stops. For example, after Pavlov's dog was conditioned to salivate at the sound of a metronome, it eventually stopped salivating to the metronome after the metronome had been sounded repeatedly but no food came. Many anxiety disorders such as post traumatic stress disorder are believed to reflect, at least in part, a failure to extinguish conditioned fear.
An avoidance response is a natural adaptive behavior performed in response to danger. Excessive avoidance has been suggested to contribute to anxiety disorders, leading psychologists and neuroscientists to study how avoidance behaviors are learned using rat or mouse models. Avoidance learning is a type of operant conditioning.
A bedwetting alarm is a behavioral treatment for nocturnal enuresis.
In Kamin's blocking effect the conditioning of an association between two stimuli, a conditioned stimulus (CS) and an unconditioned stimulus (US) is impaired if, during the conditioning process, the CS is presented together with a second CS that has already been associated with the unconditioned stimulus.
In psychology, a stimulus is any object or event that elicits a sensory or behavioral response in an organism. In this context, a distinction is made between the distal stimulus and the proximal stimulus.
Sensory preconditioning is an extension of classical conditioning. Procedurally, sensory preconditioning involves repeated simultaneous presentations (pairing) of two neutral stimuli, i.e. stimuli that are not associated with a desired unconditioned response.
Conditioned place preference (CPP) is a form of Pavlovian conditioning used to measure the motivational effects of objects or experiences. This motivation comes from the pleasurable aspect of the experience, so that the brain can be reminded of the context that surrounded the "encounter". By measuring the amount of time an animal spends in an area that has been associated with a stimulus, researchers can infer the animal's liking for the stimulus. This paradigm can also be used to measure conditioned place aversion with an identical procedure involving aversive stimuli instead. Both procedures usually involve mice or rats as subjects. This procedure can be used to measure extinction and reinstatement of the conditioned stimulus. Certain drugs are used in this paradigm to measure their reinforcing properties. Two different methods are used to choose the compartments to be conditioned, and these are biased vs. unbiased. The biased method allows the animal to explore the apparatus, and the compartment they least prefer is the one that the drug is administered in and the one they most prefer is the one where the vehicle is injected. This method allows the animal to choose the compartment they get the drug and vehicle in. In comparison, the unbiased method does not allow the animal to choose what compartment they get the drug and vehicle in and instead the researcher chooses the compartments.
The comparator hypothesis is a psychological model of associative learning and performance. To understand the model, it helps to consider how associative learning is usually studied. For example, to study the learning of an association between cues, such as lights and sounds, and an outcome such as food, an experimenter typically pairs the cues and the food a number of times and then tests with one or more of the cues to see if a response has been learned. Most theories of associative learning have assumed that phenomena of interest depend on what happens during the learning phase. The comparator hypothesis assumes, on the contrary, that what happens during the learning phase is fairly simple, and that most interesting phenomena depend on what happens during the test phase. The comparator hypothesis arose primarily in response to so-called “cue competition” effects. If for example in classical conditioning, two conditioned stimuli A and B are presented with an unconditioned stimulus, one may find on test that the subject responds to A or to B or to both or not very much to either. How can one account for such varied results?
Memory consolidation is a category of processes that stabilize a memory trace after its initial acquisition. A memory trace is a change in the nervous system caused by memorizing something. Consolidation is distinguished into two specific processes. The first, synaptic consolidation, which is thought to correspond to late-phase long-term potentiation, occurs on a small scale in the synaptic connections and neural circuits within the first few hours after learning. The second process is systems consolidation, occurring on a much larger scale in the brain, rendering hippocampus-dependent memories independent of the hippocampus over a period of weeks to years. Recently, a third process has become the focus of research, reconsolidation, in which previously consolidated memories can be made labile again through reactivation of the memory trace.
Proboscis extension reflex (PER) is the extension by an insect with an extendable proboscis of her proboscis as a reflex to antennal stimulation. It is evoked when a sugar solution is touched to a bee's antenna.
Spontaneous recovery is a phenomenon of learning and memory that was first named and described by Ivan Pavlov in his studies of classical (Pavlovian) conditioning. In that context, it refers to the re-emergence of a previously extinguished conditioned response after a delay. Such a recovery of "lost" behaviors can be observed within a variety of domains, and the recovery of lost human memories is often of particular interest. For a mathematical model for spontaneous recovery see Further Reading.
External inhibition is the observed decrease of the response of a conditioned reaction when an external (distracting) stimulus that was not part of the original conditioned response set is introduced. This effect was first observed in Ivan Pavlov's classical conditioning studies where the dogs would salivate less when presented with the sound of the tuning fork in the distracting context of a passing truck. External inhibition is important for its main principle in classical conditioning where a conditioned response may decrease in magnitude after the external stimulus is introduced. This is especially advantageous for when trying to disassociate conditioned stimulus and responses. A practical example is where students who become anxious upon standing in front of the class to give a presentation may feel less anxiety if their friends were sitting in front of the student presenting. The positive association of speaking to friends may distract the student from associating speaking to the entire class with anxiety.
The Perruchet effect is a psychological phenomenon in which a dissociation is shown between conscious expectation of an event and the strength or speed of a response to the event. This can be demonstrated by sequential analyses of consecutive trials such as eye blinking conditioning, electrodermal shocks and cued go/no-go task. The dissociation design differentiates the automatic associative strength and propositional expectation's effects on associative learning and conditioning, i.e., the cognitive learning process with relationship between events.
Evaluative conditioning is defined as a change in the valence of a stimulus that is due to the pairing of that stimulus with another positive or negative stimulus. The first stimulus is often referred to as the conditioned stimulus and the second stimulus as the unconditioned stimulus. A conditioned stimulus becomes more positive when it has been paired with a positive unconditioned stimulus and more negative when it has been paired with a negative unconditioned stimulus. Evaluative conditioning thus refers to attitude formation or change toward an object due to that object's mere co-occurrence with another object.
Association in psychology refers to a mental connection between concepts, events, or mental states that usually stems from specific experiences. Associations are seen throughout several schools of thought in psychology including behaviorism, associationism, psychoanalysis, social psychology, and structuralism. The idea stems from Plato and Aristotle, especially with regard to the succession of memories, and it was carried on by philosophers such as John Locke, David Hume, David Hartley, and James Mill. It finds its place in modern psychology in such areas as memory, learning, and the study of neural pathways.
