Psyc 100 Classical Conditioning Worksheet Answers Sample

Part 1: Key Definitions

Classical conditioning, formally established by Pavlov (1927), operates on precise stimulus-response mechanisms. The Unconditioned Stimulus (UCS) naturally and automatically triggers a physiological response without prior learning; in Pavlov's 1897 experiments, the UCS was meat powder. The Unconditioned Response (UCR) constitutes the unlearned, naturally occurring reaction to the UCS, specifically the canine salivation reflex. A Conditioned Stimulus (CS) begins as an initially neutral environmental trigger that, following repeated temporal pairings with a UCS, reliably elicits a conditioned response. The Conditioned Response (CR) represents the learned psychological or physiological reaction to the formerly neutral CS. Acquisition of the CR typically stabilizes after 5-10 initial pairings (Pavlov, 1927).

Part 2: Scenario Identification

Scenario 1: Taco Sickness

John developed an illness after consuming tacos. Currently, olfactory exposure to tacos induces nausea. The UCS is the pathogen (bacteria or virus) present in the consumed tacos. The UCR is the physiological illness and subsequent nausea caused directly by the pathogen. The CS is the smell of the tacos, functioning as the previously neutral stimulus. The CR is the conditioned nausea elicited by the olfactory cue alone.

Scenario 2: Bell and Dog

A dog hears a bell immediately prior to receiving food, resulting in salivation. Eventually, auditory exposure to the bell alone triggers salivation. The UCS is the food presentation. The UCR is the innate salivation reflex. The CS is the auditory tone of the bell. The CR is the conditioned salivation triggered by the bell.

Scenario 3: Fear of White Rats

Parallel to the 1920 Little Albert methodology, an abrupt, loud noise accompanies the presentation of a white rat, eliciting a fear response in a child. Subsequently, visual exposure to the white rat alone provokes crying. The UCS is the loud, sudden noise. The UCR is the innate fear or startle reflex (crying). The CS is the white rat. The CR is the conditioned fear response to the visual stimulus of the rat (Watson & Rayner, 1920).

Part 3: Extinction and Spontaneous Recovery

Extinction manifests following the repeated, isolated presentation of the conditioned stimulus without the accompanying unconditioned stimulus. To successfully extinguish the CR in Scenario 1, John requires repeated olfactory exposure to the taco smell (CS) in the strict absence of the pathogen (UCS). Prolonged exposure without adverse physiological consequences will progressively weaken the CS-CR association until the smell no longer elicits nausea (Watson & Rayner, 1920).

References

Pavlov, I. P. (1927). Conditioned Reflexes: An Investigation of the Physiological Activity of the Cerebral Cortex. Oxford University Press.

Watson, J. B., & Rayner, R. (1920). Conditioned emotional reactions. Journal of Experimental Psychology, 3(1), 1-14.