2008.10.29LEE JI HOON

question1. What is the meaning of evolutionary

psychology.2. Why is the taste aversion learning

important.

ContentsTaste Aversion LearningEvolutionary PsychologyBiological ConstraintsSociobiology

Taste Aversion LearningThe Old Woman explained, what the bird that

eats a poisonous butterfly acquires is a taste aversion: a marked dislike for a particular food.

What is important biologically is that the taste aversion be powerful and that it develop immediately

Conditioning Explanations for Taste Aversions

A. US (effective stimulus, cyanide in stomach) + CS (Neutral stimulus; sight/taste of poisoned

moth)

UR

(unconditioned response; illness)

B. UR (unconditioned response;

illness)

cR

Problems with Classical Conditioning Explanations of Taste AversionsSeveral problems of Pavlovian classical

conditioning explanation1. maintains that conditioning results from the

repeated; yet taste aversion learning often occurs in a single trial.

2. depend on contiguity. In taste aversion learning, the response occurs many minutes, or even hours after the CS

3. any neutral stimulus can be associated with any US if paired with it often enough, but, certain associations are never learned, but other are learned extremely readily.

One-Trial Acquisition of Taste AversionsA single experience is sufficient.

Delayed Conditioning of Taste AversionsTrace conditioning is very difficult unless the

time lapse between CS and US is extremely short, but not in rats.

In humans, too, taste aversion are learned by children and by adults.

Problems with Classical Conditioning Explanations of Taste Aversions

Latent Inhibition in Taste Aversion LearningLatent inhibition, kind of selectivity

Selectivity in Taste Aversion LearningRats – color, flavor Quail – color,

flavor

Problems with Classical Conditioning Explanations of Taste Aversions

The Phenomenon of BlockingPretraining Conditioning Testing Response

A Group(control)

None Noise + Light -> Shock Light Freezing(high fear)

B Group(blocking)

Noise -> Shock Noise + Light -> Shock Light Bar Pressing(no fear)

A representation of Kamin’s study of blocking in classical conditioning.

Explanations of BlockingThe Rescorla-Wagner Model

Classical conditioning is the formation of an association between a CS and a US.

Strength of the association between CS and US Associative strength

A Biological Explanation: Learning What Goes with WhatContiguity is not as important as the information

a stimulus provides about the probability of other events.

Connection or expectation

Higher-Order ConditioningThe relations learned in classical conditioning

are not limited between The CS and US

Conditioning as Biological AdaptationLearning is essentially an adaptive process.

Explanations of Blocking

Darwinian Natural selection and PsychologyDarwin’s theory of natural selection

profoundly influenced conditioning theorists.In brief, conditioning may be described as the

survival (and death) of responses. Behaviors whose consequences are most adaptive are most likely to survive.

Evolutionary PsychologyThe defining characteristic of evolutionary

psychology, then, is its attention to biology and genetics as sources of explanation for human learning and behavior.

AutoshapingInstinctive drift

AutoShaping

Food

US

A. Lighted Key

CS

Peck

URB. Lighted

Key CS

Peck UR =(Autoshaped

behavior)

Autoshaped responses are remarkably persistent, and remarkably resistant to extinction.

Instinctive Driftthe tendency of an organism to revert to

instinctive behaviors that can interfere with the conditioned response.

Instinctive drift presents a good example of classical conditioning. But it is an example that emphasizes the importance of biology

Biological constraintsThe main characteristic of evolutionary

psychology is its attention to biological influences on learning and behavior.

Autoshaping, instinctive drift, and the learning of taste aversions are striking examples of biological influences.

A biological constraint is an inborn predisposition that makes certain kinds of learning highly probable and easy and other kinds improbable and very difficult.

Sociobiology: A Precursor of Evolutionary PsychologyThe systematic study of the biological basis of

all social behavior.The study of the biological determination of

social behavior among all species.Based on ethologyInclusive Fitness and Altruism

The end..Thank you!

question1. What is the meaning of evolutionary

psychology.2. Why is the taste aversion learning

important.