6.3 Conditioned Fear Response

Introduction to Conditioning and Preparedness

  • Continuation from previous discussion on conditioning.

  • Focus on how evolution has influenced our learning processes.

Concept of Preparedness

  • Definition: Preparedness refers to the predisposition to learn certain types of information more quickly than others based on evolutionary factors.

  • Example of fear conditioning experiments:

    • Participants shown either non-threatening images (e.g., flowers) or threatening ones (e.g., guns and snakes).

    • A mild electric shock is paired with these images to create a conditioned response.

Fear Conditioning Paradigm

  • Conditioned Stimulus (CS): The images shown (e.g., flower, gun, snake) that are initially neutral.

  • Unconditioned Stimulus (US): The electric shock that naturally elicits a response (pain/discomfort).

  • After multiple pairings, the aim is to see if the neutral stimulus can elicit a stress response on its own.

Experiment Findings

  • Flowers:

    • Minimal fear response observed; participants did not associate fear with this benign stimulus.

  • Guns:

    • Slightly higher conditioned response, but still not as strong as biological threats.

  • Snakes:

    • Significant increase in skin conductance response when paired with shocks, indicating a much stronger fear conditioning.

    • Suggests our evolutionary history influences how quickly and strongly we learn to fear certain stimuli.

  • Discussion:

    • Evolutionarily, humans faced threats from snakes, which led to a faster learning response compared to modern threats like guns.

    • Suggests that biological threats have a more immediate impact on our survival instincts as opposed to recently introduced dangers.

Conditioned Taste Aversions

  • Definition: A conditioned response to food that leads to strong aversion following a nauseating episode following the food intake, often leading to avoidance.

  • Personal anecdote many may relate to: Eating food, feeling sick, and developing a lasting dislike toward that food.

Characteristics of Conditioned Taste Aversions

  • Learning in One Trial: Unlike typical conditioning, where multiple pairings are needed, taste aversions can occur after a single instance.

  • Delayed Association:

    • The sickness can occur hours or even a day after consuming the food, breaking the traditional idea of learning that typically requires temporal closeness.

    • This can cause confusion regarding the source of the sickness, yet the aversion still develops due to biological imperatives.

Physiological Basis for Taste Aversions

  • Specialized nerve connections exist between our digestive system and the brain, facilitating rapid learning about potentially harmful substances.

  • Relevance of Survival: The quicker we learn about harmful foods, the better chance we have at survival, which has influenced our evolution.

Specific Conditions for Conditioned Taste Aversions

  • More likely to occur with unfamiliar foods or those we have not previously encountered significantly.

  • Example: Eating salmon for the first time may lead to a strong aversion following illness, whereas repeated exposure to salmon usually results in a positive association and no aversion.

  • Further anecdote: A typical night out with alcohol can lead to a strong aversion to a particular drink if one becomes ill after consuming it.

Conclusion

  • Both preparedness in fear conditioning and taste aversion highlight how evolution shapes our learning mechanisms to prioritize survival.

  • These adaptations illustrate a mismatch in our responses to modern threats versus evolutionary threats, emphasizing the need for continued study on how evolution intertwines with cognitive processes.