Pavlov’s Experiment: The Basic Conditioning Experiment

·         Unconditional Stimulus (US): in classical conditioning, the stimulus that elicits the response before conditioning occurs

·         Unconditional response (UR): In classical conditioning, an innate response that is elicited by a stimulus in the absence of conditioning

·         Conditional Stimulus (CS): An initially neutral stimulus (like a bell) that begins to elicit a conditional response after it has been paired with an unconditional stimulus 

·         Conditional Response (CR): the response that is elicited by the conditional stimulus after classical conditioning had taken place. The response is “conditional” in the sense that it depends on the conditioning experience

·        The transfer of learned response from one stimulus  a similar stimulus

o   After conditioning with a tone of certain pitch, animals with also respond to other CSs of similar pitch

Note: for example: if your original stimulus is a specific tone at 100khz, it doesnt matter if you increase 120 khz or decrease the tone at 80khz, there will be equal less response CR (Generalization Decrument both way)  

But If you increase the loudness of soun, you potentially could increase CR  

·        The learning of an association between a stimulus and a response

o   The bell (CS) and drooling to the food (UR) occurred together in time , and there an association was made

§  Bell (CS) à Salivation (UR)

·        the learning of an association between two stimuli

o   associate the bell (CS) with another stimulus, the food (US)     Bell à Food

·        Experiment: Rats are conditioned a fear of light by pairing the light with a loud sound that arouses fear. Both group are conditioned, but group 1 is habituated with the loud sound and thus decrease its fear of the loud sound. Group 2 (control) didn’t receive habituation of the loud sound. When both group are tested for their fear of light, group 1 were less scared of the light.

o   Why should habituation of the loud sound cause fear of the light to change, since the loud sound was never paired with the light again after fear of it had been habituated?

§  Ans: learning in the first phase must be S-S learning, in group 1 the rat first learned to associate the light with the loud sound, creating fear due to loud sound. After habituation and during final test, the light activated the “modified” loud sound and thus, rats became less fearful of the light.

·        a Classical conditioning procedure in which a conditional response (CR) is acquired by a neutral stimulus when the latter is paired with a stimulus that had previously been conditioned

o   Ex) The light CS is first paired with the food US until the light elicits a CR quite often (1^st phase). Then a new CS (a tone) is now paired with the light (2^nd phase) and as a result the tone (new CS) now elicits a CR, even though it has never been paired directly with a US

·        A classical conditioning procedure in which two neutral stimuli are first paired with each other, and then one of them is a paired with an unconditioned stimulus. When the other neutral stimulus is tested, it evoked a conditional response, even though it was never paired with the unconditional stimulus itself.

o   Ex) two different CS are associated/paired (light and tone) in phase 1. Then in phase 2, light is associated with US food only. Then as a result, the tone will elicits a food CR, even if it was never paired with the US food.

§  PURE S-S learning because 2 stimulus are paired before the light ever had a reason to elicit the CR

 any of several methods for studying classical conditioning

·        The range of responses studied reinforces the point that conditioning control many different types of behavior in many different species

o   Expt) Eyeblink conditioning in rabbits. Two CSs, light and tone are associated with US which is the shock/puff of air that triggers the blinking reaction UR. Over trials, the rabbit will response to CSs causing a CR, blinking eye.

§  Optimal Time interval between trials are good for getting good eye blink responding to the CS 

a method for studying classical conditioning in which the conditional  is associated with a mild electric shock and the CS comes to suppress an ongoing behavior, such as lever-pressing reinforced by food.

·        Expt) Fear Conditioning in Rats:

o   The rat is trained to push a lever for food in a standard skinner box. But after the rat pushes the lever to get its food, a light is shown (CS) and wait .5 second, then the light CS is paired with a shock US. Note: the lever-press response has nothing to do with the presentation of the CS or US. After being CS being paired with the shock US many times, the rat will stop pressing the lever if the light CS is present. Thus, the bar-pressing response is suppressed by the CS light à conditioned fear

a form of sign tracking in which a keylight that is a paired with food elicits automatic pecking in the pigeon even when the keylight was only presented. It has been a popular method for studying classical conditioning.

·        Note: since the keylight is paired with the food, the bird will automatically first peck the key when the light comes on, even if the food is not present later on. On a more interesting fact, the bird will first peck the key when the light comes, even if it has to walk a certain distance to do the action when the food is right next to it!

·        Sign tracking: moving toward a positive stimulus or away from a negative stimulus

Things that Affect the Strength of Conditioning:

-Time

·        Rule of Thumb: Conditioning works best when the CS occurs BEFORE the US, the CS must signal that a US is about to happen

·        a classical conditioning procedure in which the unconditional stimulus US is presented after the conditional stimulus CS had been terminated. Basically, where the CS and US are separated by a gap.

o   Problem: The longer the trace intervals, the less effective the conditioning, although trace procedures produce good learning.

o   Intertrial Interval: the period of time between two successive trials

§  A 2^nd stimulus that acts as a test trial 

·        In classical conditioning, a procedure in which the conditional stimulus CS and unconditional stimulus US are presented at the same time.

o   Weak conditioning due to a shorter CS-US interval, but can help us differentiate between actual performance and learning, since the time interval CS-US allows the animal to perform. But in simultaneous conditioning, if the animal actually perform effectively, then it truly learned.   

·        A classical conditioning procedure in which the conditioned stimulus is presented after the unconditioned stimulus has occurred. Can lead to either no conditioning, conditioned excitation, or conditioned inhibition depending on the timing of the two stimuli. US comes first, then CS.

o   Don’t produce effective conditioning , but you can treats the method as “CS prepare you for NO US”, basically a conditioned inhibitor

o   Ex) In dear conditioning, the onset of shock US can arouse fear US, but a CS like a light associated with “NO US aka no shock” can produce a CR which is relief.

Conditioning trials separated by a long intertribal interval

·        Better conditioning than mass-trials because learning requires that the subject reheares the CS and US together in memory for awhile after each conditioning trial. A new trial thus can interrupt this rehearsal process if occurs too soon. 

conditioning trials separated by a short intertrial interval

·        Note: “the success of conditioning depends on the ratio between ‘the time between trials’ and the ‘time in the CS’. The ratio is bigger when time between trials is increased, but not if the time in the CS and the time between trials are both multiplied by the same factor.

Novelty of the CS and the US:

interference with conditioning that is produced by repeated exposures to the conditional stimulus before conditioning begins. “preexposure to the CS can interfere with conditioning”.

·        Ex) Your attention to the CS bell, will decrease with time (habituation) 

Novelty of the CS and the US:

US preexposure effect:

Intensity of the CS and US:

·        In conditioning, the stronger the US, the better the results. Intensity of the US or the US’s magnitude roughly determines the upper limit of learning.  Note: too powerful of a stimulus might invoke its own scary responses.

Problem: sometime the CS will revoke a response before the actual US. Ex) in the eyeblink experiment, if we use a light CS and a puff of air US to trigger blinking UR/CR. Sometime, the light CS will cause blinking without the usage of the US itself.

·        There are two processes beside true conditioning that might make the subject respond more and more to the CS

o   a process whereby a conditional stimulus can evoke responding because the organism had merely been exposed to the unconditioned stimulus, rather than true associative learning.

§  Ex) you are first exposure to repeated puff of air US, then thus over time, any sudden stimulus will make you blink. Thus, if we use a CR light then the sudden stimulus will cause you to blink, even if there was not an association between US or CS.