Presentation on theme: "IVAN PAVLOV 1847 - 1936. The Adventures of the Black Girl in Her Search for God George Bernard Shaw (1933) “What am I running away from? I’m not afraid."— Presentation transcript:
The Adventures of the Black Girl in Her Search for God George Bernard Shaw (1933) “What am I running away from? I’m not afraid of that dear noisy old man.” “Your fears and hopes are only fancies” said a voice close to her, proceeding from a very shortsighted elderly man in spectacles who was sitting on a gnarled log. “In running away you were acting on a conditioned reflex. It is quite simple. Having lived among lions you have from your childhood associated the sound of a roar with deadly danger. Hence your precipitate flight when that superstitious old jackass brayed at you. This remarkable discovery cost me twenty-five years of devoted research, during which I cut out the brains of innumerable dogs, and observed their spittle by making holes in their cheeks for them to salivate through instead of through their tongues. The whole scientific world is prostrate at my feet in admiration of this colossal achievement and gratitude for the light is has shed on the great problems of human conduct.” “ Why didn’t you ask me?” said the black girl. “I could have told you in twenty-five seconds without hurting those poor dogs.”
“Your ignorance and presumption are unspeakable” said the old myop. “The fact was known of course to every child; but it had never been proved experimentally in the laboratory; and therefore it was not scientifically known at all. It reached me as an unskilled conjecture: I handed it on as science. Have you ever performed an experiment, may I ask?” “Several” said the black girl. “I will perform one now. Do you know what you are sitting on?” “I am sitting on a log grey with age, and covered with an uncomfortable rugged bark” said the myop. “You are mistaken” said the black girl. “You are sitting on a sleepy crocodile.” With a yell which Micah himself might have envied, the myop rose and fled frantically to a neighboring tree, up which he climbed catlike with an agility which in so elderly a gentleman was quite superhuman. “Come down” said the black girl. “You ought to know that crocodiles are only to be found near rivers. I was only trying an experiment. Come down.” The Adventures of the Black Girl in Her Search for God George Bernard Shaw (1933)
Pavlov's significance: Integrated traditions of reflexology and associationism Recognized significance of psychic secretion. Provided basis for investigating neuroscience of classical conditioning (Kandel) Defined modern concepts of conditioning. First empirical model of associationism.
Categories of Behavior UnconditionedConditioned Voluntary or operant Looking Babbling Crawling Reading Writing Fence jumping Involuntary or respondent Pupil response GSR response GSR when telling a lie
Pavlov’s apparatus for studying conditioned salivary response
Training CS (tone) + US (food in mouth) After Training (conditioning) CS (tone) CR (salivation) Classical Conditioning Before Training US (food in mouth) UR (salivation) CS (bell) No relevant response
Development of a Conditioned Reflex CS US Drops of Saliva CS US Drops of Saliva CS US Drops of Saliva
The stimulus in a classical conditioning experiment that elicits the unconditional response. Unconditional Response (UR) The response in a classical conditioning experiment that is elicited by the unconditional stimulus. Conditional Stimulus (CS) The stimulus in a classical conditioning experiment that is neutral with respect to the unconditional response. Conditional Response (CR) The response in a classical conditioning experiment that is elicited by the conditional stimulus. Unconditional Stimulus (US)
DISCRIMINATION LEARNING: Initial generalization from CS+ to CS Gradual weakening of response to CS Subject responds mainly to CS+ at the end of discrimination training CS+ alternates with CS- e.g., Buzzer Food (Acquisition) Light No Food (Extinction)
14:8 10:8 12:8 Initial Discrimination Establishing an “EXPERIMENTAL NEUROSIS” S+ S- 16:8 9:8 Final Discrimination
CS (Bell) CR (Salivation) US (Food) UR (Salivation) CONDITIONING Trial 1:Later Trials:
Classical Conditioning (Type S) Initially, US UR food salivation CS orienting (?) buzzer turning towards source no salivation (or minimal salivation) After multiple pairings of CS and US: CS CR buzzer salivation Signal a reinforcing event (an unconditioned stimulus “US”), e.g., sound a buzzer (a conditioned stimulus) before delivering food. Buzzer food CS US
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