Ch. 4: Concepts in Psych I

Landmark Studies and Concepts in Comparative Psychology

Overview of Key Figures in Comparative Psychology

  • Edward Thorndike

    • Key Contributions:

    • Focused on trial and error learning through experiments involving animals in "puzzle boxes."

    • Studied operant conditioning and its principles.

  • Ivan Pavlov

    • Key Contributions:

    • Known for foundational work in classical/Pavlovian conditioning.

    • Conducted studies on associative learning, particularly with dogs in relation to salivation and the ingestion of food.

Classical Conditioning - Pavlov's Observations

  • Initial Observations:

    • Pavlov observed that dogs began salivating before receiving food.

  • Reasoning:

    • Salivating before food was not considered an innate response; instead, it indicated that dogs made associations between stimuli (sight/smell of food, presence of an investigator) and the food itself.

    • This led to systematic studies that continued for several decades.

  • Critical Insight:

    • Pavlov noted, "It is pretty evident that under natural conditions the normal animal must respond…to other events which…signal the approach of these stimuli."

Terminology in Classical Conditioning

  • Key Concepts:

    • Unconditioned Response (UR):

    • A regular and measurable response occurring without training; for example, salivating when food is presented.

    • Unconditioned Stimulus (US):

    • A stimulus that naturally elicits the unconditioned response; for example, food.

    • Conditioned Stimulus (CS):

    • Initially neutral stimulus that does not elicit the unconditioned response but becomes associated with the unconditioned stimulus; for example, a bell.

    • Conditioned Response (CR):

    • A response similar to the unconditioned response that is elicited by the conditioned stimulus; e.g., salivating in response to a bell.

Process of Classical Conditioning

  • Conditioning Sequence:

    • Over several days, a dog is presented with a bell (CS) immediately before receiving food (US).

    • During some trials, the bell is presented alone (CS without US).

    • If the dog salivates in response to the bell, this response is considered a conditioned response.

  • Responses Analysis:

    • Initially, conditioned and unconditioned responses were perceived as identical except for their triggers, but it's now recognized that they can differ qualitatively.

Pavlov's Findings on Acquisition and Extinction

  • Acquisition:

    • Refers to the decrease in latency to respond to the conditioned stimulus over time, as measured by the volume of saliva produced during conditioning trials.

  • Extinction:

    • Refers to the process where the conditioned response diminishes when the conditioned stimulus is presented without the unconditioned stimulus, leading to increased latency of salivation.

Effective Conditions for Classical Conditioning

  1. Order of Stimuli:

    • The conditioned stimulus must be presented before the unconditioned stimulus to establish a clear signal for the animal.

    • If reversed, acquisition of the conditioned response is reduced or absent.

  2. Latency Minimization:

    • The latency between the CS and US should be minimal to promote unambiguous associations; this tolerance may vary by species and nature of the stimuli.

  3. Uniqueness of CS:

    • The conditioned stimulus should be unique to the unconditioned stimulus to maintain its predictive validity.

  4. Adaptability:

    • Effective conditioning can diminish over time if previously used conditioned stimuli lose their predictive utility.

    • Animals must dissolve outdated associations while forming new relevant ones.

Adaptive Nature of Learning

  • Significance:

    • Animals are predisposed to learn about stimuli that predict significant life events (e.g., food, mates, predators).

    • Improved success of animals that detected and learned such signals is a characteristic of evolution.

  • Example Study:

    • Shriner (1999) studied golden-mantled ground squirrels subjected to novel auditory stimuli associated with predation; showed enhanced vigilance after conditioning.

Applications of Classical Conditioning

  • Behavior Modification:

    • Classical conditioning can be applied in clinical contexts, such as treating human enuresis (bedwetting). In the context of treating human enuresis (bedwetting) using classical conditioning: * **Unconditioned Stimulus (US)**: A full bladder. * **Unconditioned Response (UR)**: Waking up in response to a full bladder. * **Conditioned Stimulus (CS)**: An alarm (e.g., from a bedwetting alarm) that sounds when wetting occurs or is about to occur. * **Conditioned Response (CR)**: Waking up in response to the alarm, and eventually, waking up purely from the sensation of a full bladder before the alarm even sounds, due to the established association.

  • Olfactory Conditioning Example:

    • Will involve honey bees (Apis mellifera) in bomb detection, demonstrating the versatility of classical conditioning in practical applications in fields like security. In the context of the olfactory conditioning example involving honey bees for bomb detection: * **Unconditioned Stimulus (US)**: A reward, such as sugar water. * **Unconditioned Response (UR)**: The bee extending its proboscis (mouthpart) to consume the sugar water. * **Conditioned Stimulus (CS)**: The specific scent associated with an explosive compound. * **Conditioned Response (CR)**: The bee extending its proboscis in response to the scent of the explosive, even when the sugar water reward is not immediately present.

Operant Conditioning - Thorndike's Findings

  • Puzzle Box Experiments:

    • Thorndike placed animals in "puzzle boxes" to study learning through trial and error.

    • Animals would accidentally perform actions that led to escape and reward.

  • Law of Effect:

    • Thorndike established this principle stating that responses followed by a satisfying state of affairs tend to be repeated.

Comparing Classical and Operant Conditioning

  • Genesis of Response:

    • Classical Conditioning: Elicited responses (subject does not control sequence of events).

    • Operant Conditioning: Emitted responses (subject's behavior controls events).

  • Nature of Association:

    • Classical: Stimulus-Stimulus (CS and US).

    • Operant: Response-Stimulus (behavior and rewards).

Principle of Intellectual Continuity

  • Concept:

    • While species may differ in specific learnings or the speed of learning, the fundamental process of learning is consistent across all species studied.

  • Application:

    • Thorndike's studies on various animals (dogs, cats, fish, monkeys, chickens) supported this principle by revealing similarities in learning processes.