Habituation

1. Habituation • Habituation is a decrease in strength of response to a repeated stimulus • Helps organisms to prevent being overwhelmed and exhausted by not responding to non-important stimuli

2. Important Abbreviations CS  Conditioned Stimulus CR Conditioned Response UCS UnConditioned Stimulus    UCR UnConditioned Response NS  Neutral Stimulus

3. Before ConditioningBell (NS) àNo salivation response Food was presented (UCS) àNaturally the animal salivates. (UCR) After ConditioningBell (CS) àSalivation response (CR)

6. Paradigm Time Simultaneous Conditioning CS ____---____ - ring bell and open meat drawerUS ____---____ Delayed conditioning CS _------------_US ______----_ Trace Conditioning CS __---______US ______---__ Temporal Conditioning US __---__---__ Backward Conditioning CS ______---_US ___---____

7. Stimulus Generalization If you condition a dog to a bell at 5000 cycles per second and you use the same bell, you get the same response.But if you ring a bell of 3000 cycles per second you get a diminished salivary response in comparison to the bell which rang at 5000 cycles per second

8. To eliminate generalization and enhance discrimination: give the animal food over several trials when the the 5,000 cycles per second bell is rung; then ring bells with frequencies close to but different from 5000 cycles per second but never feed the dog, the dog will then lean to discriminate between a 5000cycles per second bell and other bells. Discrimination

9. John Watson & his assistant Rosalie Rayner "Little Albert" Experiment - The conditioned fear of a white rat In the beginning little Albert played freely with a white rat.  But later, Watson paired a loud noise with the presentation of the rat.   Albert became afraid of the rat, and subsequently other small animals. Mary Cover Jones – helped with behavioral psychology and the treatment of phobias.  Invented systematic desensitization (a treatment for phobias). Conditioned Fear

10. Conditioned Food Aversion – if you get sick after eating something, there is a likelihood that you will not choose to eat it again, that is, you will avoid the food. This was used by shepherds who wanted to protect their flock, they would put out tainted meat (which made them sick). Thereafter the coyotes no longer bothered the sheep.

11. Conditioned Immune Response - The immune response can be classically conditioned. - Example: if a drug which lowers the immune system is paired over several trials with a specific taste (saccharin) the animal's immune system will be lowered by the taste alone.

12. Homeostasis - an animal's body strives to maintain a constant physiological state.

13. If a rat is put in a cold dark ice box, his body temperature drops.   After exposing the rat in this situation several times, it will be conditioned. If the ice box is no longer cooled and the rest of the situation remains the same, what will happen when the animal is put in the box? Will the animal's body temperature increase or will it decrease?

14. Paradoxically the animal's body temperature will increase! The rat's body will compensate for the cold, even though there is none - his body temperature will therefore rise. This is an example of a: Conditioned Compensatory Response.

15. Tolerance – Decreased effectiveness of a drug through repeated exposure (physiological, functional, and learned). Learned tolerance – Conditioned tolerance that is created by a conditioned compensatory response. Example: if a drug is taken repeated with friends, then friends become a CS that elicits a Conditioned Compensatory Response that keeps you from getting too high. But later if you take the drug alone, the usual compensatory response is not elicited (because the cue, friends is not present). When alone you have a higher likelihood of overdosing. This can be demonstrated experimentally in animal models.