Historical Background of Classical Conditioning Based on the

Historical Background of Classical Conditioning • Based on the concept of reflex –Recall that Descartes introduced the idea of the reflex –Russian physiologist, I. M. Sechenov (1863) "Reflexes of the Brain" applied the idea of the reflex to the activities of the cerebral hemispheres –based on the knowledge available in his day of the physiology of the central nervous system. • Russian physiologist Ivan P. Pavlov –influenced by Sechenov's view that the brain activity was organized by reflexes –Had a dim view of Psychology as a science "In fact it is still open to discussion whether psychology is a natural science, or whether it can be regarded as a science at all. “ (Pavlov, 1927 p. 4)

Historical Background of Classical Conditioning • Preferred to follow Descartes idea of the reflex as the basis for explaining everything – ""playfulness, " "fear, " "anger, " and so forth, will soon be demonstrated as reflex activities of the subcortical parts of the brain. " (p. 5) – All forms of behavior and cognition could be explained by reflexes such as the "Freedom Reflex" or "Investigatory Reflex“ (p. 11) – "Physiologists have studied and are studying at the present time these numerous machine-like, inevitable reactions of the organism-reflexes existing from the very birth of the animal, and due therefore to the inherent organization of the nervous system. “ (p. 8) – Reflexes can be of two kinds: positive or negative, excitatory or inhibitory – A connection or continuation between simplest reflex and instinct • for example: building of a nest • regard it as a chain-reflex where one reflex initiates the next • material is gathered and carried to the site chosen • there it is built up and strengthened

Historical Background of Classical Conditioning • He was studying the physiology of digestion when his students/assistants noticed a funny thing – Dogs would salivate when he put the food powder in their mouths. – But experienced dogs would salivate when the experimenter walked in the room or at the sight of food – They called this "psychic secretions" which are responses that occur in advance of getting the food • Experiments of Vul'fson and Snarskii – Natural stimuli such as food, sour water or sand would elicit a salivary reflex • • sight of natural stimuli or experimenter would also elicit salivary reflex use black sour water to elicit salivary reflex just black water would also elicit the reflex now called object learning, association of black and sour characteristics of the water

Classical Conditioning Paradigm • Present two different stimuli together as a pair – For example Pavlov used • clicking of a metronome • followed by food which produces salivation • Four major terms apply to Pavlovian Conditioning experiments – Unconditioned stimulus (US): Biologically potent stimulus (i. e. , food) that reliably evokes reflexive reaction – Unconditioned response (UR): The reflex response triggered by the US (i. e. , salivation to food) – Conditioned stimulus (CS): Biologically weak stimulus (i. e. clicking of a metronome) that may evoke an orienting response, but will not elicit an UR such as salivation – Conditioned response (CR): The learned response which is elicited by the CS in absence of the US (i. e. no food just salivation to the clicking sound)

Salivary Reflex Conditioning • Salivary Conditioning Apparatus see Figure 3. 1 • During conditioning various stimuli can be paired with a dish of food placed in front of the dog • The device pictured here is more elaborate than the one Pavlov used in his early experiments • Pavlov paired the clicking of a metronome with food • Before any training: – food (US) produces salivation (UR); this the salivary reflex – clicking sound (CS) does not produce salivation • After a few pairings of CS [clicking] with US [food] dogs began to salivate to just the clicking sound • the CR is Salivating to the CS [clicking] only

Salivary Conditioning Apparatus Similar to Figure 3. 1 in the textbook. An apparatus for Pavlovian conditioning. A tube carries saliva from the dog’s mouth to a lever that activates a recording device (far left). During conditioning, various stimuli can be paired with a dish of food placed in front of the dog. The device pictured here is more elaborate than the one Pavlov used in his early experiments.

Fear Conditioning Procedure • Using an aversive (US) • such as brief shock delivered to the feet through a metal grid • produces a defensive response (UR) including • jumping, vocalizing then freezing • So this is a complex pattern of behavior not just a simple reflex • The CS may be a light or tone • CS tone followed by US shock • After a few pairings of CS - US • the CS tone only will produce CR freezing

Fear Conditioning Procedure

FIGURE 3. 2 Acquisition of conditioned freezing to an auditory CS (white noise) in laboratory rats during noiseshock conditioning trials. Each data point shows the percentage of time the rats were observed freezing during each CS presentation (based on Reger et al. , 2012). The Principles of Learning and Behavior, 7 e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Fear Conditioning Procedure • The typical conditioned response (CR) of rats is freezing behavior • Freezing behavior is not always measured directly • Freezing will interrupt other on going behaviors such as eating • Can also measure conditioned fear by observing how the CS disrupts the animal’s ongoing behavior • A popular technique is the Conditioned Emotional Response (CER) procedure – Also called Conditioned Suppression

Conditioned Emotional Response (CER) note: this is still fear conditioning • First train “hungry” rats to bar press for food until they reach stable baseline of responding in an operant chamber • Then give pairings of Tone ---- Shock in a separate chamber to produce fear conditioning • Put the “hungry” rat back in the operant chamber and allow them to bar press to get food – Present the tone fear signal – the tone produces freezing which suppresses bar pressing • Can also be tested with lick suppression – “thirsty” Rats trained to lick a water spout – Present the tone fear signal while they are licking the spout

Watson’s Little Albert case study • At 9 months of age • Tested him for fear of objects and live animals such as a rat • No evidence of fear to the rat • Found that he was startled by the sound of hammer striking steel bar behind his back • At 11 months of age • Condition Albert to fear the white rat • Present rat (CS) and make loud noise (US) • After 2 pairings Albert cried and tried to crawl away when rat was presented

Watson’s Little Albert case study • After 7 days - tested fear response again – Showed some fear response to rat • After 5 more pairings Albert cried and tried to crawl away when rat was presented • After 5 days - tested generalization • Showed strong fear response to rat, dog, rabbit, and sealskin coat • Negative response to Santa mask and Watson’s (white) hair • Played with familiar blocks and Watson’s assistants’ hair

Conditioned Eyeblink • The procedure for classical conditioning of the eye-blink response. • Use an aversive air puff US to produce reflexive UR eye blink • CS tone followed by US air puff • Usually requires many trials to get effective conditioning • CS tone alone will produce CR eyeblink

The Principles of Learning and Behavior, 7 e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Taste Aversion Learning (Poison avoidance learning) • Procedures – – CS is a novel-flavored food or drink such Saccharin or Peppermint Schnapps US can be a drug such as Li. Cl, radiation, toxins UR is the illness (nausea) CR is nausea, feeling ill when the CS flavor is presented alone • Difficult to measure sickness directly so decrease in drinking or eating is used to infer illness • Special features of conditioned taste aversions (CTA) – One-trial learning – Long-delay between CS and US • Common occurrence in humans from toxins in food, too many alcoholic drinks or cancer treatments

Note: low preference is an indication of nausea FIGURE 3. 7 Mean percent preference for the saccharin CS flavor during a test session conducted after the CS flavor was paired with X irradiation (the US) or sham exposure. Percent preference is the percentage of the participant’s total fluid intake (saccharin solution plus water) that consisted of the saccharin solution. During conditioning, the interval between exposure to the CS and the US ranged from 0 to 24 hours for different groups of rats. (Based on “Trace Conditioning with X-rays as an Aversive Stimulus, ” by J. C. Smith and D. L. Roll, Psychonomic Science, 1967, 9 pp. 11– 12. )

Sign Tracking (Autoshaping) • Functional background: Birds come into the world biologically prepared to peck at objects in the environment – Young birds very quickly learn to direct their pecking more at edible items such as seeds and less toward non-edible items such as pebbles – birds learn what food looks like and approach and peck those items that have the appearance of food – Literally means tracking (following) signals (visual, odor) for food • The sign tracking procedure with Pigeons • Much of the research has been done using pigeons as subjects – – – US food (grain) will elicit UR pecking at the grain CS Key light: a light comes on behind a translucent disk called a key CS Key light presented before food (grain) is given Important: Food is given whether the pigeons peck at the key light or not CR pecking at the Key light Works best when CS "sign" is spatially separated from the US "goal"

Sign Tracking (Autoshaping) • Sign Tracking also occurs as part of reproductive behavior • Male quail are attracted to and approach the females • Sexual conditioning procedure with Quail (males) • CS – block of wood presented at one end of the chamber • US – female quail presented at the other end of the chamber • UR – approaching and copulating with the female • CR – approaching block of wood • Wood block (CS) presented before door to female (US) is opened • Male approaches the wood block (CR)

The Principles of Learning and Behavior, 7 e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Sign Tracking (Autoshaping) • Sign stimuli as a conditioned stimulus (CS) • In the natural environment the cues (stimuli) associated with food are usually part of the food itself. • But in the laboratory the CS "sign" and US food are artificially separated so that responding to the CS can be observed independent of responding to the food • The CS need not look like the real thing • It simply needs to be within the same sensory modality • The CS "sign" is physically separated from the US food to a distance that allows the experimenter to clearly distinguish between sign-directed responding and food-directed responding. • Form of the CR in Sign Tracking • The type of response "CR" an animal makes matches the characteristics of the US being delivered. • Different type of pecking for grain vs water

Sign Tracking VS Goal Tracking • Rats in a small operant chamber with lever and food cup • Presentation of Lever CS followed by Food to the cup US • 1/3 of the rats approach touch and chew the lever – These rats are sign tracking – These rats also show more response to drugs of abuse – Related to genetics for exploration “seeking” behavior • 1/3 of the rats approach and poke their head into the cup – These rats are goal tracking • 1/3 of the rats do some of both behavior

Sign Tracking Blocks of 50 Goal Tracking The Principles of Learning and Behavior, 7 e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

• Are there examples of sign tracking with humans? • sign stimuli such as. . ? ? ? • Are there examples of goal tracking with humans? • goal stimuli such as. . ? ? ? • Other examples with humans?