Instrumental Conditioning Overview

Instrumental Conditioning: Introduction

• Instrumental conditioning involves learning where a stimulus is a result or consequence of a behavior.
• The behavior is necessary to produce a desired outcome.
• Instrumental behavior arises because it has previously been effective in producing certain consequences.

Instrumental Conditioning: Thorndike's Findings

• The "law of effect" states that if a response in the presence of a stimulus is followed by a satisfying event, the association between the stimulus and response strengthens.
• If the response is followed by an undesirable event, the association weakens.
• Thorndike's experiments used animal boxes to study learning through trial and error.
• His experiments distinguished between discrete trials and free-operant trials.

Modern Instrumental Conditioning: Discrete-Trial Procedures

• Willard Stanton Small conducted research similar to Thorndike's, using animal boxes to study instrumental learning.
• Training trials began with placing the animal in an apparatus followed by removing it after the instrumental response.
• Mazes were used to measure running speed and latency.

Modern Instrumental Conditioning: Free-Operant Procedures

• B.F. Skinner developed free-operant procedures which allowed animals to repeat an instrumental response without constraint.
• These procedures are used to study behavior continuously.
• An example of an operant response is a lever press.
• Operant responses are defined in how they operate on the environment.
• Any response needed to yield a desired outcome is an instrumental response.

Instrumental Conditioning Procedures: Magazine Training and Shaping

• Magazine training teaches the animal to associate a stimulus (e.g., a sound) with food delivery.
• Shaping involves progressively rewarding closer approximations of the desired behavior until the desired response is achieved.
• Successful shaping clarifies the desired response and divides the progression from the starting point to the goal into appropriate training phases, these are successive approximations.

Instrumental Conditioning Procedures: Positive Reinforcement vs. Positive Punishment

• Positive reinforcement: A response produces a pleasant stimulus.
• Positive punishment: A response produces an unpleasant stimulus.
• Positive reinforcement increases the rate of a response, whereas positive punishment decreases it.
• Examples provided include being rewarded for studying versus a punishment for not studying.

Instrumental Conditioning Procedures: Negative Reinforcement vs. Negative Punishment

• Negative reinforcement: A response eliminates or prevents an unpleasant stimulus.
• Negative punishment (omission training): A response eliminates or prevents a pleasant stimulus
• Negative reinforcement increases the response rate and Negative punishment decreases it.

Instrumental Response: Variability

• Participants can be rewarded for variations in their responses which encourage creativity
• Uniformity and stereotypy aren't inevitable outcomes of instrumental responses.
• Variability can be encouraged by using reinforcement structures.

Constraints on Instrumental Conditioning: Belongingness

• Responses are more likely to be learned if they belong with the reinforcer based on evolutionary history
• Examples include opening a latch, pulling a string, or manipulating objects to release confinement.
• Instinctive drift refers to instinctive behaviours interfering with the learned response

Instrumental Reinforcer: Response-Reinforcer Relation

• The quality, quantity, and previous reinforcement are important in instrumental conditioning.
• Getting immediate reinforcement after a behavior is more effective.
• Reinforcer's relationship to the response, and the time between is critical.
• Behavioral contrast occurs when a small reward might be considered poor after a strong reward.

Instrumental Reinforcer: Delay of Reinforcement

• Delay in reinforcement reduces the effectiveness of the response-reinforcer association.
• Immediate reinforcement results in more learning than delayed reinforcment.

Superstition

• Superstitious behaviors are associated with accidental reinforcement.
• Terminal responses appear near the time of a reinforcement occurrence.
• Temporal contiguity (the time proximity between a response and a reinforcer) is a critical factor in instrumental conditioning.
• Interim responses occur in the middle interval between reinforcement events.

Learned Helplessness

• Learning a lack of control over a negative stimulus can impede future learning.
• Animals exposed to inescapable shock perform poor in subsequent learning trials.
• The learned helplessness effect occurs due unpredictable and uncontrollable negative stimuli.
• The activity deficit hypothesis involves decreased activity as a response to inescapable shocks which leads to limited learning.