Ch 5 Evolutionary Psychology Learning biology and the

Ch. 5 Evolutionary Psychology: Learning, biology, and the Brain, part 1 2008. 10. 29 LEE JI HOON

question 1. What is the meaning of evolutionary psychology. 2. Why is the taste aversion learning important.

Contents Taste Aversion Learning Evolutionary Psychology Biological Constraints Sociobiology

Taste Aversion Learning The 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) B. UR (unconditioned response; illness) c. R

Problems with Classical Conditioning Explanations of Taste Aversions Several problems of Pavlovian classical conditioning explanation 1. 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.

Problems with Classical Conditioning Explanations of Taste Aversions One-Trial Acquisition of Taste Aversions A single experience is sufficient. Delayed Conditioning of Taste Aversions Trace 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 Learning Latent inhibition, kind of selectivity Selectivity in Taste Aversion Learning Rats – color, flavor Quail – color, flavor

The Phenomenon of Blocking Pretraining 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 Blocking The 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 What Contiguity is not as important as the information a stimulus provides about the probability of other events. Connection or expectation

Explanations of Blocking Higher-Order Conditioning The relations learned in classical conditioning are not limited between The CS and US Conditioning as Biological Adaptation Learning is essentially an adaptive process.

Darwinian Natural selection and Psychology Darwin’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 Psychology The defining characteristic of evolutionary psychology, then, is its attention to biology and genetics as sources of explanation for human learning and behavior. Autoshaping Instinctive drift

Auto. Shaping A. Lighted Key CS B. Lighted Key CS Food US Peck UR =(Autoshaped behavior) Autoshaped responses are remarkably persistent, and remarkably resistant to extinction.

Instinctive Drift the 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 constraints The 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 Psychology The systematic study of the biological basis of all social behavior. The study of the biological determination of social behavior among all species. Based on ethology Inclusive Fitness and Altruism

The end. . Thank you!

question 1. What is the meaning of evolutionary psychology. 2. Why is the taste aversion learning important.