Principles of Associative and Non-Associative Learning

Syllabus Highlights and Course Introduction

Definition and Nature of Learning

Learning is defined as an enduring change in behavior mechanisms resulting from experience. It is crucial to understand the difference between learning and performance: performance changes do not necessarily indicate learning, and learning can occur without visible performance improvements.

Associative Learning involves forming associations between stimuli/events (CS-US) or behavior and outcomes (R-S). Learning can be conscious or unconscious (procedural/implicit learning) and supports emotions, motivations, decision-making, and survival adaptation.

Types of Learning

• Associative Learning: Predictive learning is observed in performance, but changes in performance do not necessarily indicate learning. Learning the association between two or more events allows an individual to predict one event based on the occurrence of another. This is a primary way we interact with our environment.
  • Classical (Pavlovian) Conditioning: A Conditioned Stimulus (CS) predicts an Unconditioned Stimulus (US), leading to a Conditioned Response (CR).
  • Instrumental/Operant Conditioning: A response leads to a specific outcome.
• Non-Associative Learning: Elicited behavior changes as a result of a repeated eliciting stimulus.
  • Habituation: A decrease in responding due to a repeated stimulus (e.g., you live by a highway and eventually stop hearing the noise).
  • Sensitization: An increase in responsiveness due to arousing stimuli (e.g., after a scary movie, you jump when a car door closes).

Procedural and Implicit Learning

Procedural or implicit learning occurs outside of our awareness; you simply "pick up" on these things. However, learning can also be maladaptive, as seen in substance use disorders, compulsive overeating, pathological gambling, and video game addiction. In these cases, the brain predicts dopamine and reward, leading to intense cravings.

Behavioral vs. Cognitive Definitions

• Behavioral: Learning is an enduring change in behavior. It must be distinguished from changes due to physical, physiological, or developmental factors. It is a highly specific adaptation to environmental constraints.
• Cognitive: Learning is the formation of a novel mental structure that indirectly manifests as behavior. It is a general adaptation across environments and species, suggesting a common learning process.

Key Pavlovian Conditioning Concepts

• US (Unconditioned Stimulus): A stimulus that naturally evokes a response (e.g., food).
• UR (Unconditioned Response): A natural response to the US (e.g., salivation).
• CS (Conditioned Stimulus): A previously neutral stimulus paired with a US to evoke a CR (e.g., a tone or light).
• CR (Conditioned Response): A learned response to the CS, often similar to the UR.

When the CS predicts the US, it leads to an anticipatory CR (excitatory conditioning). Measurement of learning includes CR magnitude, probability, or latency during probe trials. Controls such as CS-only, US-only, and unpaired presentations are needed to rule out non-associative effects like habituation or sensitization.

Non-Associative Learning Details

• Habituation: Stimulus-specific decreased responding after repeated exposure.
• Dishabituation: The recovery of a response when the stimulus changes.
• Sensitization: A generalized increase in arousal and responsiveness due to a strong stimulus.

Experimental Study of Learning

Key elements of scientific study include testable hypotheses, systematic variable manipulation, quantifiable outcomes, rigorous controls, and sufficient sample sizes. Animal research (especially with rodents) is essential due to genetic and brain similarities. Experiments produce facts, which are synthesized into theories to explain and predict behavior.

Behavioral Phenomena and Examples

• Little Albert Experiment: A conditioned fear response to a white rat paired with a loud noise.
• Mary Cover Jones’ Counterconditioning: Reducing fear by pairing a feared stimulus with a positive one (e.g., a rabbit with cookies).
• Modal Action Patterns (MAPs): Species-specific fixed action sequences triggered by releasing stimuli.
• Supernormal Stimulus: Artificially exaggerated stimuli that elicit stronger responses than natural ones.

Elicited Behavior and Reflexes

A reflex is an involuntary, often instantaneous response to a stimulus. Examples include the patellar reflex, pupillary reflex, sneezing, infant head-turning, and the withdrawal reflex. Modal Action Patterns (MAPs) are response patterns exhibited by most members of a species, triggered by specific releasing stimuli.

Pavlovian Conditioning: Controls and Examples

Absence of evidence is not evidence of absence. Through learning, one develops the capability to perform, but this may remain latent. Examples of appetitive Pavlovian CRs include:

• Consummatory responding (e.g., a dog salivating to a bell).
• Sign-tracking (e.g., a bird pecking at a light or a person approaching a Starbucks sign).
• Goal approach (e.g., entering a store with a "For Sale" sign).
• Conditioned taste preference (e.g., coffee becoming pleasant after repeated positive associations).
• Drug conditioning (e.g., morphine leading to a preparatory hypoalgesia response).

Higher Order and Inhibitory Conditioning

Higher order conditioning occurs when a previously learned CS reinforces an association with a new stimulus without the US (e.g., pairing a light with a bell that already causes salivation). Inhibitory conditioning occurs when a cue (CS-) signals the absence of a US, requiring an excitatory CS+ to establish expectation.

Examples of Conditioned Inhibition

• Standard Inhibition: A bully (CS+) signals teasing, but a bully plus a teacher (CS-) signals no teasing (safety).
• Negative CS-US Contingency: A restaurant (CS+) signals food, but a restaurant plus a "closed" sign (CS-) signals no food.

Tests for Conditioned Inhibition

• Summation Test: A suspected inhibitor (B) is presented with a known excitor (A). If B is inhibitory, the response to the compound (A+B) will be lower than the response to A alone.
• Retardation of Acquisition Test: It takes longer to turn a conditioned inhibitor into an excitor than it does to train a neutral stimulus.

Factors Controlling Pavlovian Learning

Strength of learning depends on timing, salience, novelty, and belongingness. The nature of the CR is dictated by the CS-US interval (imminence), the form of the US/CS, and the predatory imminence continuum (ranging from anxiety to flight). Stimulus Salience (intensity and biological significance) and CS-US belongingness also play vital roles. Remember: just because you do not see a CR does not mean learning did not occur; you may have simply missed the most appropriate measure of that learning.